Do you need to know, when is the best time to go to Vietnam? Then you should take a look here, what weather you can expect there during the year.
The climate of Vietnam is tropical in south and monsoonal in north. There is a hot, rainy season from May to September, and warm and dry season from October to March. You can expect lower temperatures in mountains.
When speaking about the usual weather in this state, the information is relevant for example for these popular places: Ba Be National Park, Ba Ria, Bac Ha, Bac Lieu, Bach Ma National Park, Bai Tu Long Bay, Bao Loc, Ben Tre, Buon Ma Thuot, Ca Mau, Ca Na, Cai Be, Cai Rong, Can Tho, Cao Bang, Cao Lãnh, Cat Ba, Cat Tien National Park, Central Coast, Central Highlands, Chau Doc, Chàm Islands, Co Loa, Co To Island, Con Dao, Cu Chi, Cua Ong, Cuc Phuong National Park, DMZ, Da Nang, Dalat, Dien Bien Phu, Dong Dang, Dong Ha, Dong Hoi, Dong Van, Gia Nghia, Giao Xuân, Gò Công, Ha Giang, Ha Long Bay, Ha Tien, Haiphong, Halong, Hanoi, Ho Chi Minh City, Hoi An, Hue, Khe Sanh, Khâm Đức, Kontum, Lao Cai, Long Xuyen, Lăng Cô, Mong Cai, Mui Ne, My Son, My Tho, Na Meo, Ngoc Hoi, Nha Trang, Ninh Binh, Northern Vietnam, Phan Rang–Tháp Chàm, Phan Thiet, Phong Nha Ke Bang, Phu Quoc, Pleiku, Quan Lan, Quy Nhon, Quảng Ngãi, Rach Gia, Sa Pa, Sa Đéc, Soc Trang, Southern Vietnam, Tam Dao, Tam Ky, Thac Mo, Thanh Hoa, Tra Vinh, Tuan Chau Island, Tây Ninh, Vi Thanh, Vinh, Vinh Long, Vung Tau, Xuan Thuy National Park.
Let's look now what weather you can expect in the area around the capital and in many other cities. The warmest month here is July, the average maximum temperature is 33.7 ℃ (92.66 ℉). The average minimum temperature in this month is 26.3 ℃ (79.34 ℉). The coldest month here is January, the average maximum temperature is 19.5 ℃ (67.1 ℉). The average minimum temperature in this month is 13.7 ℃ (56.66 ℉). The most rainy month here is August, the average number of rainy days is 16.5. The least rainy month here is December, the average number of rainy days is 5.9. 
When travelling to some places in Vietnam, always consider the altitude of the the place as well. The highest point here is Fan Si Pan (3144 m) and the lowest point is South China Sea (0 m). So there are huge differences in altitudes in this country and the weather is very different in them therefore. Keep in mind, that the temperature usually decreases by 1.2 - 1.9 ℃ (2.2 - 3.5 ℉) per 200 m (656 ft), depending on the other conditions. (And we should add, that in the very special condition named thermal inversion even the temperature may be higher in higher altitudes.)
Typical (usual) weather in Vietnam in January is this: The average highest temperature in Vietnam in January is 19.5 ℃ (67.1 ℉). The average lowest temperature is 13.7 ℃ (56.66 ℉). At the beginning of January you can expect higher temperatures, the average highest temperature is around 20.75 ℃ (69.35 ℉). At the end of January you can expect higher temperatures, the average highest temperature is around 19.85 ℃ (67.73 ℉). The average number of rainy days in January is 8.5. The average rainfall is 18.5 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 10:52 (hours and minutes), in the middle of the month 10:59 and at the end of the month 11:11.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Vietnam in February is this: The average highest temperature in Vietnam in February is 20.2 ℃ (68.36 ℉). The average lowest temperature is 15.5 ℃ (59.9 ℉). At the beginning of February you can expect lower temperatures, the average highest temperature is around 19.85 ℃ (67.73 ℉). At the end of February you can expect higher temperatures, the average highest temperature is around 21.75 ℃ (71.15 ℉). The average number of rainy days in February is 11.1. The average rainfall is 26.4 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 11:11 (hours and minutes), in the middle of the month 11:26 and at the end of the month 11:43.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.
Typical (usual) weather in Vietnam in March is this: The average highest temperature in Vietnam in March is 23.3 ℃ (73.94 ℉). The average lowest temperature is 17.9 ℃ (64.22 ℉). At the beginning of March you can expect lower temperatures, the average highest temperature is around 21.75 ℃ (71.15 ℉). At the end of March you can expect higher temperatures, the average highest temperature is around 25.55 ℃ (77.99 ℉). The average number of rainy days in March is 14.7. The average rainfall is 44.1 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 11:43 (hours and minutes), in the middle of the month 12:02 and at the end of the month 12:20.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Vietnam in April is this: The average highest temperature in Vietnam in April is 27.8 ℃ (82.04 ℉). The average lowest temperature is 21.4 ℃ (70.52 ℉). At the beginning of April you can expect lower temperatures, the average highest temperature is around 25.55 ℃ (77.99 ℉). At the end of April you can expect higher temperatures, the average highest temperature is around 30 ℃ (86 ℉). The average number of rainy days in April is 13.5. The average rainfall is 91.7 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 12:20 (hours and minutes), in the middle of the month 12:37 and at the end of the month 12:54.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.
Typical (usual) weather in Vietnam in May is this: The average highest temperature in Vietnam in May is 32.2 ℃ (89.96 ℉). The average lowest temperature is 24.1 ℃ (75.38 ℉). At the beginning of May you can expect lower temperatures, the average highest temperature is around 30 ℃ (86 ℉). At the end of May you can expect higher temperatures, the average highest temperature is around 32.5 ℃ (90.5 ℉). The average number of rainy days in May is 14. The average rainfall is 193 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 12:54 (hours and minutes), in the middle of the month 13:08 and at the end of the month 13:18.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Vietnam in June is this: The average highest temperature in Vietnam in June is 32.8 ℃ (91.04 ℉). The average lowest temperature is 26.2 ℃ (79.16 ℉). At the beginning of June you can expect lower temperatures, the average highest temperature is around 32.5 ℃ (90.5 ℉). At the end of June you can expect higher temperatures, the average highest temperature is around 33.25 ℃ (91.85 ℉). The average number of rainy days in June is 14.5. The average rainfall is 235.9 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 13:18 (hours and minutes), in the middle of the month 13:24 and at the end of the month 13:23.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Vietnam in July is this: The average highest temperature in Vietnam in July is 33.7 ℃ (92.66 ℉). The average lowest temperature is 26.3 ℃ (79.34 ℉). At the beginning of July you can expect lower temperatures, the average highest temperature is around 33.25 ℃ (91.85 ℉). At the end of July you can expect lower temperatures, the average highest temperature is around 32.95 ℃ (91.31 ℉). The average number of rainy days in July is 15.8. The average rainfall is 288.2 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 13:23 (hours and minutes), in the middle of the month 13:18 and at the end of the month 13:07.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Vietnam in August is this: The average highest temperature in Vietnam in August is 32.2 ℃ (89.96 ℉). The average lowest temperature is 25.5 ℃ (77.9 ℉). At the beginning of August you can expect higher temperatures, the average highest temperature is around 32.95 ℃ (91.31 ℉). At the end of August you can expect lower temperatures, the average highest temperature is around 31.75 ℃ (89.15 ℉). The average number of rainy days in August is 16.5. The average rainfall is 321.3 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 13:07 (hours and minutes), in the middle of the month 12:53 and at the end of the month 12:37.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Vietnam in September is this: The average highest temperature in Vietnam in September is 31.3 ℃ (88.34 ℉). The average lowest temperature is 25.2 ℃ (77.36 ℉). At the beginning of September you can expect higher temperatures, the average highest temperature is around 31.75 ℃ (89.15 ℉). At the end of September you can expect lower temperatures, the average highest temperature is around 29.7 ℃ (85.46 ℉). The average number of rainy days in September is 13.4. The average rainfall is 272 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 12:37 (hours and minutes), in the middle of the month 12:19 and at the end of the month 12:01.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Vietnam in October is this: The average highest temperature in Vietnam in October is 28.1 ℃ (82.58 ℉). The average lowest temperature is 22.6 ℃ (72.68 ℉). At the beginning of October you can expect higher temperatures, the average highest temperature is around 29.7 ℃ (85.46 ℉). At the end of October you can expect lower temperatures, the average highest temperature is around 26.85 ℃ (80.33 ℉). The average number of rainy days in October is 9. The average rainfall is 133.2 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 12:01 (hours and minutes), in the middle of the month 11:44 and at the end of the month 11:27.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Vietnam in November is this: The average highest temperature in Vietnam in November is 25.6 ℃ (78.08 ℉). The average lowest temperature is 18.3 ℃ (64.94 ℉). At the beginning of November you can expect higher temperatures, the average highest temperature is around 26.85 ℃ (80.33 ℉). At the end of November you can expect lower temperatures, the average highest temperature is around 23.8 ℃ (74.84 ℉). The average number of rainy days in November is 6.4. The average rainfall is 43.9 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 11:27 (hours and minutes), in the middle of the month 11:11 and at the end of the month 10:59.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.Typical (usual) weather in Vietnam in December is this: The average highest temperature in Vietnam in December is 22 ℃ (71.6 ℉). The average lowest temperature is 15.6 ℃ (60.08 ℉). At the beginning of December you can expect higher temperatures, the average highest temperature is around 23.8 ℃ (74.84 ℉). At the end of December you can expect lower temperatures, the average highest temperature is around 20.75 ℃ (69.35 ℉). The average number of rainy days in December is 5.9. The average rainfall is 23.1 mm (look here, what this number means). When planning your travel, please, keep in mind, that actual weather may differ from these average values. The length of the day at the beginning of this month is approximately 10:59 (hours and minutes), in the middle of the month 10:52 and at the end of the month 10:51.These numbers above are valid primarily for the capital and the area around it. It is important to say, that the weather may differ significantly in different altitudes, especially in mountains.| Hanoi | temperature: - | highest temperature: 22 ℃ (71.6 ℉) | lowest temperature: 15.6 ℃ (60.08 ℉) | rainfall: 23.1mm | rainy days: 5.9 |
| Ho Chi Minh City | temperature: - | highest temperature: 31 ℃ (87.8 ℉) | lowest temperature: 21.3 ℃ (70.34 ℉) | rainfall: 47.7mm | rainy days: 6.8 |
| Da Nang | temperature: - | highest temperature: 25.6 ℃ (78.08 ℉) | lowest temperature: 19 ℃ (66.2 ℉) | rainfall: 200.6mm | rainy days: 19 |