Are you planning a trip to Hanoi and wondering about the best time to visit? What Are The Four Distinct Seasons In Hanoi? SIXT.VN is here to guide you through Hanoi’s unique seasonal changes, ensuring you experience the best of this vibrant city with our premier travel services. From airport transfers to hotel bookings, exploring Hanoi has never been easier. Uncover the best time to visit, discover seasonal attractions, and plan your perfect trip with our insider tips.
Contents
- 1. Understanding Hanoi’s Four Seasons: A Traveler’s Guide
- 2. Spring in Hanoi: Renewal and Festivities
- 2.1. Weather and Climate
- 2.2. Top Attractions and Activities
- 2.3. Spring Festivals and Events
- 2.4. What to Pack for Spring in Hanoi
- 2.5. Tips for Travelers
- 3. Summer in Hanoi: Heat and Rain
- 3.1. Weather and Climate
- 3.2. Top Attractions and Activities
- 3.3. Summer Festivals and Events
- 3.4. What to Pack for Summer in Hanoi
- 3.5. Tips for Travelers
- 4. Autumn in Hanoi: The Best Time to Visit
- 4.1. Weather and Climate
- 4.2. Top Attractions and Activities
- 4.3. Autumn Festivals and Events
- 4.4. What to Pack for Autumn in Hanoi
- 4.5. Tips for Travelers
- 5. Winter in Hanoi: Cool and Dry
- 5.1. Weather and Climate
- 5.2. Top Attractions and Activities
- 5.3. Winter Festivals and Events
- 5.4. What to Pack for Winter in Hanoi
- 5.5. Tips for Travelers
- 6. Seasonal Cuisine: Hanoi’s Culinary Delights
- 6.1. Spring Cuisine
- 6.2. Summer Cuisine
- 6.3. Autumn Cuisine
- 6.4. Winter Cuisine
- 7. Accommodation Tips for Each Season
- 7.1. Spring Accommodation Tips
- 7.2. Summer Accommodation Tips
- 7.3. Autumn Accommodation Tips
- 7.4. Winter Accommodation Tips
- 8. Transportation Options: Getting Around Hanoi
- 8.1. Walking
- 8.2. Motorbike Taxi (Xe Om)
- 8.3. Cyclo
- 8.4. Taxi and Ride-Hailing Services
- 8.5. Bus
- 8.6. SIXT.VN Car Rental and Airport Transfers
- 9. Packing Essentials for Hanoi: A Seasonal Checklist
- 9.1. Spring Packing Essentials
- 9.2. Summer Packing Essentials
- 9.3. Autumn Packing Essentials
- 9.4. Winter Packing Essentials
- 10. Making the Most of Your Trip with SIXT.VN
- 10.1. Airport Transfers
- 10.2. Hotel Bookings
- 10.3. Car Rentals
- 10.4. Tour Packages
- 10.5. Customer Support
- FAQ: Planning Your Trip to Hanoi
1. Understanding Hanoi’s Four Seasons: A Traveler’s Guide
Hanoi experiences four distinct seasons, each offering a unique charm and set of attractions: Spring, Summer, Autumn, and Winter. Each season impacts tourism differently, presenting both opportunities and challenges for travelers.
- Spring (March to May): This is the season of renewal, with mild temperatures and blooming flowers. Expect occasional drizzles.
- Summer (June to August): Hot and humid, with frequent heavy rains and occasional typhoons.
- Autumn (September to November): Considered the best time to visit, with pleasant temperatures, clear skies, and a gentle breeze.
- Winter (December to February): Cool and dry, with occasional cold spells.
Understanding these seasons will help you pack appropriately and plan activities that best suit the weather. Let’s dive deeper into each season.
2. Spring in Hanoi: Renewal and Festivities
Spring in Hanoi, from March to May, is a time of renewal and vibrant festivities. The weather is mild and pleasant, with average temperatures ranging from 20°C to 25°C (68°F to 77°F). This season is characterized by blooming flowers, lush greenery, and occasional light drizzles, making it an ideal time to explore the city’s outdoor attractions.
2.1. Weather and Climate
The spring season in Hanoi is generally mild and comfortable, making it perfect for sightseeing and outdoor activities.
Month | Temperature (°C) | Temperature (°F) | Rainfall (mm) |
---|---|---|---|
March | 20-23 | 68-73 | 40 |
April | 23-27 | 73-81 | 60 |
May | 25-30 | 77-86 | 90 |
- Temperature: The average temperature ranges from a comfortable 20°C to 25°C (68°F to 77°F).
- Rainfall: Expect occasional light drizzles, but overall, rainfall is relatively low compared to other seasons.
- Humidity: Humidity levels are moderate, making it comfortable for outdoor activities.
2.2. Top Attractions and Activities
Spring is an excellent time to explore Hanoi’s top attractions and participate in various activities:
- Hoan Kiem Lake: Enjoy a leisurely walk around the lake and visit Ngoc Son Temple.
Alt text: Tranquil view of Hoan Kiem Lake with Ngoc Son Temple reflected in the calm water during springtime in Hanoi.
- Temple of Literature: Explore Vietnam’s first university, built in 1070, and admire its ancient architecture.
- Old Quarter: Wander through the narrow streets, shop for souvenirs, and sample local street food.
- Perfume Pagoda: Take a day trip to this famous pilgrimage site, nestled in the mountains.
- Hoa Lo Prison: Learn about Vietnam’s history at this former prison, also known as the “Hanoi Hilton.”
2.3. Spring Festivals and Events
Spring is also a time of vibrant festivals and cultural events in Hanoi:
- Tet Nguyen Dan (Lunar New Year): Celebrated in late January or early February, Tet is the most important festival in Vietnam. Experience traditional customs, colorful decorations, and delicious food.
- Lim Festival: Held in Bac Ninh province (near Hanoi) in February, this festival features traditional Quan Ho folk songs.
- Co Loa Festival: Celebrated in March or April, this festival commemorates King An Duong Vuong and the ancient Co Loa Citadel.
2.4. What to Pack for Spring in Hanoi
Packing for spring in Hanoi requires some consideration:
- Light clothing: Pack light, breathable clothing suitable for warm temperatures.
- Rain gear: Bring a light jacket or umbrella for occasional drizzles.
- Comfortable shoes: Wear comfortable shoes for walking and exploring the city.
- Sunscreen: Protect your skin from the sun with sunscreen.
- Insect repellent: Use insect repellent to avoid mosquito bites.
2.5. Tips for Travelers
- Book accommodations in advance: Spring is a popular time to visit Hanoi, so book your accommodations in advance to secure the best deals. With SIXT.VN, finding the perfect hotel is simple.
- Learn basic Vietnamese phrases: Knowing a few basic phrases will enhance your interactions with locals.
- Be prepared for crowds: Popular attractions can be crowded, especially during festivals.
- Try local cuisine: Sample traditional Vietnamese dishes like pho, banh mi, and bun cha.
- Stay hydrated: Drink plenty of water to stay hydrated in the warm weather.
3. Summer in Hanoi: Heat and Rain
Summer in Hanoi, from June to August, is characterized by hot and humid weather with frequent heavy rains and occasional typhoons. Temperatures can soar to as high as 35°C (95°F), making it the least comfortable time to visit for many travelers. However, with proper planning, you can still enjoy Hanoi’s attractions during this season.
3.1. Weather and Climate
The summer months in Hanoi are hot and humid, with high temperatures and significant rainfall.
Month | Temperature (°C) | Temperature (°F) | Rainfall (mm) |
---|---|---|---|
June | 28-35 | 82-95 | 150 |
July | 28-35 | 82-95 | 200 |
August | 27-34 | 81-93 | 180 |
- Temperature: Average temperatures range from 28°C to 35°C (82°F to 95°F).
- Rainfall: Expect frequent heavy rains, especially in the afternoons and evenings.
- Humidity: Humidity levels are very high, often exceeding 80%.
3.2. Top Attractions and Activities
Despite the heat and rain, there are still plenty of attractions and activities to enjoy in Hanoi during the summer:
- Museums and Indoor Attractions: Visit the Vietnam National Museum of Fine Arts, the Vietnam Museum of Ethnology, or the Ho Chi Minh Museum to escape the heat.
Alt text: The entrance to the Vietnam National Museum of Fine Arts, offering a cool indoor escape during the hot Hanoi summer.
- Water Puppet Show: Enjoy a traditional water puppet show at the Thang Long Water Puppet Theatre.
- Shopping Malls: Explore air-conditioned shopping malls like Vincom Center or Lotte Center Hanoi.
- West Lake: Take a boat ride on West Lake or enjoy a meal at one of the lakeside restaurants.
- Bat Trang Ceramic Village: Visit this traditional pottery village and try your hand at making ceramics.
3.3. Summer Festivals and Events
While summer is not as festival-heavy as spring, there are still some events to look out for:
- Doan Ngo Festival (Double Fifth Festival): Celebrated in June, this festival involves eating special foods like sticky rice dumplings and drinking herbal wine to ward off diseases.
- Ghost Festival (Vu Lan): Observed in August, this festival is a time to honor ancestors and offer prayers for the deceased.
3.4. What to Pack for Summer in Hanoi
Packing for summer in Hanoi requires careful consideration to stay comfortable in the heat and rain:
- Light, breathable clothing: Pack loose-fitting clothes made of cotton or linen.
- Rain gear: Bring a waterproof jacket or umbrella for heavy rains.
- Sunscreen: Protect your skin from the strong sun.
- Hat and sunglasses: Shield yourself from the sun with a hat and sunglasses.
- Insect repellent: Mosquitoes are more prevalent in the summer, so use insect repellent.
- Waterproof bags: Protect your electronics and valuables from the rain.
3.5. Tips for Travelers
- Stay hydrated: Drink plenty of water to avoid dehydration in the heat.
- Avoid peak heat hours: Plan outdoor activities for early morning or late afternoon to avoid the hottest part of the day.
- Use air conditioning: Seek out air-conditioned spaces like shopping malls, museums, and cafes.
- Be aware of typhoons: Keep an eye on weather forecasts and be prepared for potential typhoons.
- Bargain at markets: If you’re shopping at outdoor markets, don’t be afraid to bargain for better prices.
- Book airport transfers: Ensure a smooth arrival with SIXT.VN’s reliable airport transfer service, avoiding the hassle of finding transportation in the heat.
4. Autumn in Hanoi: The Best Time to Visit
Autumn in Hanoi, from September to November, is widely considered the best time to visit. The weather is pleasant and mild, with clear skies and a gentle breeze. The city transforms into a picturesque landscape with golden leaves and a romantic atmosphere.
4.1. Weather and Climate
Autumn offers the most comfortable weather conditions in Hanoi:
Month | Temperature (°C) | Temperature (°F) | Rainfall (mm) |
---|---|---|---|
September | 25-32 | 77-90 | 100 |
October | 23-30 | 73-86 | 60 |
November | 20-27 | 68-81 | 40 |
- Temperature: Average temperatures range from 20°C to 30°C (68°F to 86°F).
- Rainfall: Rainfall is minimal, with clear skies and sunny days.
- Humidity: Humidity levels are low, making it comfortable for outdoor activities.
4.2. Top Attractions and Activities
Autumn is the perfect season to explore Hanoi’s outdoor attractions and enjoy various activities:
- Hoan Kiem Lake: Enjoy a peaceful walk around the lake and admire the autumn foliage.
Alt text: Picturesque autumn scene at Hoan Kiem Lake, with golden leaves and a serene atmosphere, perfect for a leisurely stroll.
- Temple of Literature: Explore the historic temple and enjoy the beautiful autumn scenery.
- Old Quarter: Wander through the streets, shop for souvenirs, and enjoy the vibrant atmosphere.
- West Lake: Rent a bike and cycle around West Lake, enjoying the cool breeze and scenic views.
- Hanoi Opera House: Attend a performance at the Hanoi Opera House and experience the city’s cultural scene.
4.3. Autumn Festivals and Events
Autumn is also a time of cultural events and festivals:
- Mid-Autumn Festival (Tet Trung Thu): Celebrated in September or October, this festival involves eating mooncakes, watching lion dances, and carrying lanterns.
- Hanoi Autumn Festival: This annual event features cultural performances, art exhibitions, and culinary delights.
4.4. What to Pack for Autumn in Hanoi
Packing for autumn in Hanoi requires versatility:
- Light clothing: Pack light, comfortable clothing for warm days.
- Light jacket or sweater: Bring a light jacket or sweater for cooler evenings.
- Comfortable shoes: Wear comfortable shoes for walking and exploring the city.
- Umbrella: Although rainfall is minimal, it’s always a good idea to bring an umbrella.
4.5. Tips for Travelers
- Book accommodations in advance: Autumn is a popular time to visit, so book your accommodations well in advance.
- Enjoy street food: Sample seasonal street food like cốm (young green rice) and roasted chestnuts.
- Visit local markets: Explore local markets like Dong Xuan Market and enjoy the vibrant atmosphere.
- Take a cooking class: Learn how to prepare traditional Vietnamese dishes.
- Use SIXT.VN for transportation: Rely on SIXT.VN for convenient and reliable transportation options, including car rentals and airport transfers.
5. Winter in Hanoi: Cool and Dry
Winter in Hanoi, from December to February, is characterized by cool and dry weather, with occasional cold spells. Temperatures can drop to as low as 10°C (50°F), making it the coldest time of the year. Despite the cold, winter in Hanoi offers a unique charm and a different perspective on the city.
5.1. Weather and Climate
Winter in Hanoi is cool and dry, with occasional cold spells:
Month | Temperature (°C) | Temperature (°F) | Rainfall (mm) |
---|---|---|---|
December | 15-22 | 59-72 | 20 |
January | 13-20 | 55-68 | 15 |
February | 15-23 | 59-73 | 20 |
- Temperature: Average temperatures range from 13°C to 23°C (55°F to 73°F).
- Rainfall: Rainfall is minimal, with dry and sunny days.
- Humidity: Humidity levels are low, making it comfortable for outdoor activities.
5.2. Top Attractions and Activities
Winter in Hanoi offers a unique set of attractions and activities:
- Hoan Kiem Lake: Enjoy a peaceful walk around the lake and experience the winter atmosphere.
- Temple of Literature: Explore the historic temple and admire its ancient architecture.
Alt text: The serene Temple of Literature in winter, providing a peaceful experience with its historic architecture and quiet atmosphere.
- Old Quarter: Wander through the narrow streets, shop for souvenirs, and enjoy the cozy atmosphere.
- Museums and Indoor Attractions: Visit the Vietnam National Museum of Fine Arts or the Ho Chi Minh Museum to escape the cold.
- Hot Spring Resorts: Take a day trip to nearby hot spring resorts like Kim Boi or Thanh Thuy.
5.3. Winter Festivals and Events
Winter is also a time of cultural events and festivals:
- Christmas: While not a traditional Vietnamese holiday, Christmas is celebrated in Hanoi with festive decorations and events.
- Tet Nguyen Dan (Lunar New Year): If Tet falls in late January or early February, you can experience the most important festival in Vietnam.
5.4. What to Pack for Winter in Hanoi
Packing for winter in Hanoi requires warm clothing:
- Warm clothing: Pack warm clothes like sweaters, jackets, and coats.
- Long pants and long-sleeved shirts: Bring long pants and long-sleeved shirts to layer your clothing.
- Scarf, gloves, and hat: Protect yourself from the cold with a scarf, gloves, and hat.
- Comfortable shoes: Wear comfortable shoes for walking and exploring the city.
5.5. Tips for Travelers
- Book accommodations with heating: Ensure your accommodations have heating to stay comfortable in the cold.
- Enjoy hot beverages: Warm up with traditional Vietnamese hot beverages like coffee or tea.
- Try winter street food: Sample winter street food like hot pho and grilled snacks.
- Visit local markets: Explore local markets and enjoy the festive atmosphere.
- Use SIXT.VN for reliable transportation: Ensure a comfortable journey with SIXT.VN’s reliable car rental and transportation services, perfect for exploring Hanoi and its surroundings in winter.
6. Seasonal Cuisine: Hanoi’s Culinary Delights
Hanoi’s cuisine is deeply influenced by its seasons, with each season offering unique ingredients and dishes. Experiencing the local cuisine is an essential part of any trip to Hanoi.
6.1. Spring Cuisine
Spring in Hanoi brings fresh and vibrant ingredients:
- Gỏi cuốn (Fresh Spring Rolls): These light and refreshing rolls are filled with vegetables, herbs, and shrimp or pork.
- Bún chả (Grilled Pork with Noodles): A Hanoi specialty, bún chả is made with grilled pork served with rice noodles and a flavorful dipping sauce.
- Nem cua bể (Crab Spring Rolls): These crispy spring rolls are filled with crab meat and served with a dipping sauce.
6.2. Summer Cuisine
Summer cuisine in Hanoi focuses on cooling and refreshing dishes:
- Phở cuốn (Pho Rolls): These rolls are made with pho noodles and filled with vegetables and herbs.
- Nộm hoa chuối (Banana Flower Salad): A refreshing salad made with banana flower, vegetables, and peanuts.
- Chè (Sweet Soup): A variety of sweet soups are popular in the summer, often made with beans, fruits, and coconut milk.
6.3. Autumn Cuisine
Autumn is the season for Hanoi’s most famous culinary delights:
- Cốm (Young Green Rice): A seasonal delicacy made from young green rice grains.
Alt text: A delicious serving of Cốm, the young green rice delicacy, symbolizing the flavors of Hanoi’s autumn season.
- Bánh cốm (Green Rice Cake): A sweet cake made from cốm and filled with mung bean paste.
- Ốc (Snails): Various types of snails are cooked and served in flavorful sauces.
6.4. Winter Cuisine
Winter cuisine in Hanoi focuses on warm and comforting dishes:
- Phở (Noodle Soup): A classic Vietnamese dish, pho is especially comforting in the winter.
- Lẩu (Hot Pot): A communal dish where ingredients are cooked in a simmering pot of broth.
- Gà tần (Stewed Chicken): A nourishing stew made with chicken and medicinal herbs.
7. Accommodation Tips for Each Season
Choosing the right accommodation is crucial for a comfortable and enjoyable trip to Hanoi. Here are some tips for each season:
7.1. Spring Accommodation Tips
- Location: Choose accommodations near Hoan Kiem Lake or the Old Quarter for easy access to attractions.
- Amenities: Look for accommodations with gardens or courtyards to enjoy the blooming flowers and greenery.
- SIXT.VN Recommendations: Consider hotels like Sofitel Legend Metropole Hanoi or Hanoi La Castela Hotel for a luxurious stay.
7.2. Summer Accommodation Tips
- Air Conditioning: Ensure your accommodation has air conditioning to stay comfortable in the heat.
- Swimming Pool: Look for hotels with swimming pools to cool off during the day.
- SIXT.VN Recommendations: Consider hotels like InterContinental Hanoi Landmark72 or JW Marriott Hotel Hanoi for their excellent facilities.
7.3. Autumn Accommodation Tips
- Balcony or Terrace: Choose accommodations with a balcony or terrace to enjoy the pleasant weather and scenic views.
- Quiet Location: Look for accommodations in quieter neighborhoods for a peaceful stay.
- SIXT.VN Recommendations: Consider hotels like The Oriental Jade Hotel or La Siesta Premium Hang Be for their charm and comfort.
7.4. Winter Accommodation Tips
- Heating: Ensure your accommodation has heating to stay warm during the cold spells.
- Cozy Atmosphere: Look for hotels with cozy fireplaces or lounges.
- SIXT.VN Recommendations: Consider hotels like Hanoi Emerald Waters Hotel & Spa or Lotte Hotel Hanoi for their warmth and comfort.
8. Transportation Options: Getting Around Hanoi
Navigating Hanoi can be an adventure in itself. Here are the best transportation options for each season:
8.1. Walking
Walking is a great way to explore the Old Quarter and Hoan Kiem Lake, especially during the cooler seasons of spring and autumn.
8.2. Motorbike Taxi (Xe Om)
Motorbike taxis are a quick and affordable way to get around Hanoi, but be sure to negotiate the price beforehand.
8.3. Cyclo
Cyclos are a traditional form of transportation that can be a fun way to see the sights, especially in the Old Quarter.
8.4. Taxi and Ride-Hailing Services
Taxis and ride-hailing services like Grab are readily available in Hanoi and offer a convenient way to get around, especially during the hot and rainy summer months.
8.5. Bus
Hanoi has an extensive bus network that is an affordable way to travel around the city.
8.6. SIXT.VN Car Rental and Airport Transfers
For the ultimate convenience and flexibility, consider renting a car from SIXT.VN or booking our reliable airport transfer service. This is especially useful if you plan to explore areas outside of Hanoi or prefer a comfortable and private mode of transportation.
9. Packing Essentials for Hanoi: A Seasonal Checklist
Packing the right items can make a big difference in your comfort and enjoyment during your trip to Hanoi. Here’s a seasonal checklist:
9.1. Spring Packing Essentials
- Light clothing
- Light jacket or sweater
- Rain gear (light jacket or umbrella)
- Comfortable walking shoes
- Sunscreen
- Insect repellent
9.2. Summer Packing Essentials
- Light, breathable clothing (cotton or linen)
- Waterproof jacket or umbrella
- Sunscreen
- Hat and sunglasses
- Insect repellent
- Waterproof bags for electronics
9.3. Autumn Packing Essentials
- Light clothing for warm days
- Light jacket or sweater for cooler evenings
- Comfortable walking shoes
- Umbrella (just in case)
9.4. Winter Packing Essentials
- Warm clothing (sweaters, jackets, coats)
- Long pants and long-sleeved shirts
- Scarf, gloves, and hat
- Comfortable, insulated shoes
10. Making the Most of Your Trip with SIXT.VN
No matter what season you choose to visit Hanoi, SIXT.VN is here to make your trip as seamless and enjoyable as possible.
10.1. Airport Transfers
Start your trip off right with our reliable and comfortable airport transfer service. Our drivers will be waiting for you at the airport and take you directly to your hotel, avoiding the hassle of finding transportation upon arrival.
10.2. Hotel Bookings
We offer a wide range of hotel options to suit every budget and preference. Whether you’re looking for a luxury hotel or a budget-friendly guesthouse, we can help you find the perfect accommodation.
10.3. Car Rentals
Explore Hanoi and its surroundings at your own pace with our car rental service. We offer a variety of vehicles to choose from, ensuring you have the perfect car for your needs.
10.4. Tour Packages
Let us take care of the planning with our customizable tour packages. We can create a tour that suits your interests and preferences, ensuring you see the best of Hanoi and its surrounding areas.
10.5. Customer Support
Our dedicated customer support team is available 24/7 to assist you with any questions or concerns you may have. We’re here to ensure your trip is as smooth and enjoyable as possible.
FAQ: Planning Your Trip to Hanoi
Q1: What is the best time to visit Hanoi?
The best time to visit Hanoi is during the autumn months (September to November) when the weather is pleasant and mild with clear skies.
Q2: What should I pack for a trip to Hanoi in the summer?
Pack light, breathable clothing, a waterproof jacket, sunscreen, a hat, sunglasses, and insect repellent.
Q3: How can I get around Hanoi?
You can get around Hanoi by walking, motorbike taxi, cyclo, taxi, bus, or car rental.
Q4: What are the must-try dishes in Hanoi?
Must-try dishes include pho, bun cha, com (young green rice), and banh mi.
Q5: What are the top attractions to visit in Hanoi?
Top attractions include Hoan Kiem Lake, the Temple of Literature, the Old Quarter, and the Ho Chi Minh Mausoleum.
Q6: Are there any festivals in Hanoi?
Yes, Hanoi hosts several festivals throughout the year, including Tet Nguyen Dan (Lunar New Year), the Mid-Autumn Festival, and the Hanoi Autumn Festival.
Q7: How do I book airport transfers with SIXT.VN?
You can easily book airport transfers on our website or through our customer support team.
Q8: What type of accommodations does SIXT.VN offer in Hanoi?
SIXT.VN offers a wide range of accommodations, including luxury hotels, budget-friendly guesthouses, and serviced apartments.
Q9: Is it safe to travel in Hanoi?
Yes, Hanoi is generally a safe city for tourists. However, it’s always a good idea to take precautions against petty theft and scams.
Q10: How can SIXT.VN help me plan my trip to Hanoi?
SIXT.VN can help you plan your trip with airport transfers, hotel bookings, car rentals, tour packages, and 24/7 customer support.
Planning a trip to Hanoi can be an exciting adventure. Understanding the four distinct seasons and utilizing SIXT.VN’s services will ensure you have a memorable and stress-free experience. Whether you’re exploring ancient temples, savoring local cuisine, or enjoying the vibrant atmosphere, Hanoi has something to offer every traveler. Let SIXT.VN be your guide to unlocking the best of this captivating city.
Ready to explore Hanoi? Contact SIXT.VN today to book your airport transfer, hotel, or car rental!
Address: 260 Cau Giay, Hanoi, Vietnam
Hotline/Whatsapp: +84 986 244 358
Website: SIXT.VN