July is summer in the North and in the Central Region of Vietnam, and rainy season in the Central Highlands and South of Vietnam. July is among the hottest months in the lowlands and part of the mountains in the North of Vietnam and in the Central Coast while it is a pleasant time in the Central Highlands and South of Vietnam.
1/ Useful Notes on the Weather Patterns in Vietnam in July
It is possible that typhoons may hit northern Vietnam from the sea which may cause cruises on Halong Bay, Bai Tu Long Bay and Cat Ba Island halted for a couple of days each time, and torrential rains and flash floods in the far-northern mountains.
There may be torrential rain and strong winds in the Central Highlands and Southern Vietnam in the second half of July. It may be extremely dangerous traveling during or right after heavy rain in these regions as there are dangers of floods and strong winds. It is extremely dangerous to travel between Da Lat and the lowland: Khanh Le Pass (between Da Lat and Nha Trang), Bao Loc Pass (between Da Lat and Dong Nai Province, Binh Thuan Province).
In the Central Highlands and Southern Vietnam, strong winds may fell trees in cities, make streets flooded, cause landslides in the mountains. Hotels selected for your holidays in the Central Highlands of Vietnam must be carefully selected. Heavy and continual rain often causes flash floods in the region at the base of the Central Highlands like Dong Nai and Binh Phuoc. The Cat Tien National Park may be flooded or have alarmingly high water levels.
For those planning vacations on the Phu Quoc Island in the second half of July, be careful with strong winds and continually torrential rain which may last for a few days and which may cause floods in several places on the island. Strong winds result in disruption of land tours and boat trips around the island; travel by air or by boat between the Phu Quoc Island (or Hon Son or Nam Du) and the inland.
2/ Winds Affecting Vietnam in July
The winds which affect Vietnam in July include the southeasterly wind and southwesterly wind. The former is moist and pleasant, and it causes occasional rains in northern Vietnam and nice temperatures during the time of its influence. The southwesterly wind is moist in the South and the Central Highlands and it causes daily short-lived rains as well as nice temperatures in these regions.
Idyllic countryside at My Duc, Ha Tay (Hanoi now) in a July heat strike
The southwesterly wind is dry and warm due to the foehn effect when it comes to the Central Coast and part of northern Vietnam (mostly the lowlands and the eastern side of the Northwest). The Central Coast suffers the most from the foehn effect in July that is why the temperatures are constantly high and there is often no rain in the whole month. The southwesterly wind may be strong and may be the predominant wind in the lowlands and the eastern side of the Northwest of Vietnam (Hoa Binh, Yen Bai, Lao Cai) which makes the air dry, the temperatures high in these regions during its influence.
The extreme Northwest of Vietnam (Son La, Dien Bien, Lai Chau) does not have much influence from the foehn effect in July and the temperatures are normally quite pleasant. It often rains in this region in July and flash floods and landslides are the possible results.
3/ The North of Vietnam
- The Northeast of Vietnam (Lang Son, Cao Bang, Bac Kan, Ha Giang, Thai Nguyen...) enjoys quite pleasant temperatures in July, 20-34oC. It rains a lot in this region in July and there are high chances of flash floods and landslides, especially in Ha Giang, Cao Bang and Bac Kan.
The Yen Tu Mountain (Quang Ninh, Northeast Vietnam) in July
- The Northwest of Vietnam has two sub-regions with slightly different weather patterns which are driven mostly by the monsoons.
+ The region in between the extreme Northwest and the Northeast (which includes Hoa Binh, Yen Bai and Lao Cai) tends to have higher temperatures than the extreme Northwest. The reason is that this region is often affected by the foehn effect in July. The temperatures are either 26-34oC or 29-38oC depending on the monsoon influence. The predominant monsoon in this region in July is not clear but it is more likely that the southwesterly along with the foehn effect has more influence. While it does not tend to rain a lot but the torrential rains may cause flash floods and landslides.
Lac Thuy, Hoa Binh (Northwest) in a heat strike in July
Sapa is on high altitude with cool temperatures (18-25oC mostly) and with cloudy skies and rains often. Mu Cang Chai have occasional thunderstorms, 20-28oC.
+ The extreme Northwest of Vietnam (which includes Son La, Dien Bien and Lai Chau) is not often affected by the foehn wind in July. In stead it is affected by the summer monsoon (southeasterly) and occasional northerly wind. The temperatures are 22-33oC. It rains a lot in the extremely Northwest in July and flash floods and landslides are often found in Son La, Dien Bien and Lai Chau.
Moc Chau Plateau normally enjoys half sunny and half cloudy days, and occasional thunderstorms, lovely temperatures, 20-27oC.
- The lowlands (including Quang Ninh – Halong Bay, Hai Phong, Thai Binh, Nam Dinh, Ninh Binh, Hanoi)
+ Halong Bay is often influenced by the northeasterly wind and often has lovely temperatures, 29-32oC.
+ The rest of the lowlands may have influence of either the summer monsoon or the southwesterly monsoon. In the former case, then the temperatures are pleasant and it rains more often. In the latter case, it is dry and hot with daily temperatures 29-38oC for weeks. The influence of which wind is not clear in July; it could be one wind of the other depending on each year but it is more likely the hot wind has more influence.
Rice fields at Hai Phong in July sunshine
4/The North of the Central Region of Vietnam
This region is dry and tend to have high temperatures due to that this region is influenced by the foehn wind strongly in July. The temperatures are 30-40oC. It is often very dry that serious droughts are more likely and high alerts of forest fires.
5/The Central Coast of Vietnam
The whole of the Central Coast has basically similar weather pattern to that of the North of the Central Region in July: dry and sunny weather, often serious lack of water, high daily temperatures for weeks, 30-40oC.
Hue Imperial Citadel in July sun
Da Nang Ba Na Hills in July
- South of the Central Coast ( Khanh Hoa - Nha Trang Beach, Ninh Thuan - Ninh Chu Beach and Binh Thuan - Mui Ne Beach) enjoys more pleasant temperatures than all the other regions in the Central Coast. It is often hot in Ninh Thuan though, 28-36oC while it is normally 26-33oC in Khanh Hoa and Binh Thuan. The region enjoys mostly sunshine daily.
6/ The Central Highlands of Vietnam
The Central Highlands are in the rainy season in July with daily rain, mostly cloudy skies and lovely temperatures, 21-31oC.
Da Lat has mild sunshine, and clouds, daily rain, lovely temperatures, 17-24oC.
In the second half of July, there may be torrential rain which may last for a few days and which may cause flash floods and landslides in the Central Highlands of Vietnam. If you plan to travel in these regions during this time, take careful considerations. If you are traveling during heavy rain, it is advised to stay indoors. Hotels selected for your holidays must be carefully assessed factoring in these risks.
7/The South of Vietnam
The South of Vietnam enjoys lovely weather in July which is middle of the rainy season. There are daily short-lived rains which may cause streets in cities (Saigon, Bien Hoa...) temporarily flooded for a couple of hours. The temperatures are very pleasant in all over the South, 26-33oC.
The Con Dao Islands and Phu Quoc Islands are both in the rainy season in July with occasional thunderstorms, cloudy skies, 28-31oC. The southwesterly wind may be strong for a few days during which time the sea is quite rough and not suitable for water sports.
It is worth noting that a strong typhoon in Northern Vietnam may make the Southwesterly Wind in southern Vietnam much stronger which may destroy houses in the Mekong Delta, fell trees in Southern Vietnam, cause big or torrential rain in Southern Vietnam and in the Central Highlands of Vietnam. Phu Quoc Island may be flooded, so are streets in cities in Southern Vietnam and in the Central Highlands of Vietnam. During the time of a typhoon in Northern Vietnam, boat trips and flights between the inland and the offshore islands like Phu Quoc, Hon Son, Nam Du, Con Dao… are canceled.
In the second half of July there be may torrential rain in Southern Vietnam which may last for several days and which fatally dangerous floods in several cities, especially those close to the base of the Central Highlands such as in and around the Cat Tien National Park, in Binh Phuoc Province… The Cat Tien National Park may be closed during the time of floods or high water levels.
