May is beginning of summer in Northern Vietnam, the dry season with warm temperatures in the Central Coast, the beginning of rainy season with mostly pleasant and sometimes warm temperatures (on low altitudes) in the Central Highlands, and the beginning of rainy season with warm temperatures Southern Vietnam.
In the Central Highlands and Southern Vietnam, the temperatures tend to be more tolerable coming towards the end of the month as there are more daily short-lived rain.
General Weather Patterns in Vietnam in May
In May the cool Northeasterly Wind (Winter Monsoon) is less likely present. But if it is, then most of Northern Vietnam will have lovely weather with extremely pleasant temperatures and mild sunshine.
The Northeast and part of the lowland of Northern Vietnam are more likely to be under impact of the Southeasterly Wind which blows inland from the sea and which makes the real-feel temperatures more pleasant. Part of the Northwest of Vietnam may also be affected by the Southeasterly Wind and heavy rain is often found in the affected areas.
The cool Northeasterly Wind may arrive when Northern Vietnam is under impact of high temperatures air troughs (which are often found in the atmosphere over the west and northwest of Vietnam), the it may cause torrential rain with strong winds, or even hails in places.
Part of the Northwest of Vietnam, sometimes lowland of Northern Vietnam, the North of the Central Coast, the Central Coast, the Central Highlands and South Vietnam is mostly under impact of the Southwesterly Winds. There are two types of the Southwesterly Winds:
- The wind from the Bengal Bay which blows through the Indian Continent, Thailand, Myanmar, Cambodia, Laos into Vietnam. This wind causes dry air and hot temperatures in the affected regions.
- The wind comes from the Equator which causes daily short-lived rain in the Central Highlands and Southern Vietnam. This wind makes the temperatures lovely in these two regions.
Due to foehn effect, both the the above Southwesterly Winds cause high temperatures in the Central Coast of Vietnam and part of the Northwest of Vietnam, sometimes even part of the lowlands of Northern Vietnam.
What to expect from your holidays to Vietnam in May?
Taking the general weather conditions in Vietnam into consideration, for those travelers planning for tours to Vietnam, then there may be some notes as follows:
- Some torrential rain in the far northern mountains should be expected. The rain may be not too long-lasting, but trails are muddy which makes trekking tours not quite lovely experiences as they should in dry times. High temperatures and often found strong sun should be taken into account for those on adventure tours, sightseeing tours. In some cases for those on sightseeing tours, you should avoid visits to tourist attractions in cities at mid day. Street food tours should be avoided in the summer.
- Families on holidays to Vietnam should make sure you have sunshade and enough drinking water, especially those with kids and/or senior travelers.
- May is a good time for junk cruises on Halong Bay as it is often clear skies and you have lovely photos of the islands in sunshine. Those on cruises on the Mekong River in Southern Vietnam should have a good time in May too.
- May is not a good time for bird watching tours as migratory bird species have traveled back to their homeland, and bird parks and national parks in Vietnam are not busy with wildlife.
- May is a good time to go for beach holidays in Vietnam and is the best time for island vacations in Vietnam. The best beaches should be in the South of the Central Coast (Quy Nhon, Phu Yen, Nha Trang, Phan Rang, Mui Ne) and South of Vietnam (Vung Tau, Long Hai). Those on boat trips and sea exploration tours like snorkeling and scuba diving should have a great time as the sea is calm, and the sea water is clear.
- The Con Dao Islands and Phu Quoc Island are the best destination for island vacations in Vietnam in May. On these islands, the sun is bright and the temperatures are mostly pleasant in May.
The drawback for tourism in May is that the Vietnamese often have long public holidays at the beginning of May and they travel. Places are very busy during public holiday occasions; prices are often very high during these times.
Paradissa Monitoring of Notable Weather Factors Affecting All of Vietnam in May 2023
At the very end of April 2023, there was a spell of the Northeasterly Wind which caused torrential rain accompanied by strong gusts of wind in the Northeast and Northwest of Vietnam. But thanks to the wind that Northern Vietnam came into May with lovely weather: mild sunshine, clouds, pleasant temperatures.
The cool wind did help to make temperatures in the Central Coast more tolerable. The South of Vietnam had been undergoing a very long heat strike with daily temperatures surpassing 37-38oC in several places.
At the end of the first week of May, there was a heat strike in most places in Vietnam from the north to the south with several places having high temperatures of 37-38oC, or even 40-43oC.
The temperatures collected in the afternoon of 6-May-2023:
Lạc Sơn (Hòa Bình) 41.7oC, Hòa Bình 41.3oC, Hồi Xuân (Thanh Hóa) 42.4oC, Quỳ Châu (Nghệ An) 42oC, Tương Dương (Nghệ An) 42.5oC, Tây Hiếu (Nghệ An) 42.5oC, Hương Khê (Hà Tĩnh) 41.3oC.
Unprecedented high temperature of 44.2oC was recorded at Tuong Duong Nghe An on 7-May; another record high of 44.1oC was recorded at Hoi Xuan (Thanh Hoa) on the same day.
At the beginning of the second week of May 2023, there was a spell of the cool Northeasterly Wind hitting Vietnam which caused sudden ending of the heat strike in the North and part of the Central Coast. There were extreme weather conditions resulted from meeting of the hot and cold air:
- There were hails in Cao Bang (Ha Quang, Tra Linh, Trung Khanh) which destroyed some agricultural crops;
- Strong gusts of wind destroyed several houses in Nghe An Province (Ky Son, Que Phong, Quy Chau);
- Strong gusts of wind and rough sea capsized, sunken or caused boats missing off the shore of Quang Binh, Quang Tri and Thua Thien-Hue.
In the South of Vietnam, there was torrential rain in most places and there was hail in Bien Hoa Dong Nai at the beginning of the second week of May. Several places were temporarily flooded. The rain seemed to have put an end to a long-going heat strike in Southern Vietnam. Rainfall from 13:00 of 08-May to 03:00 A.M ngày 09-May in South of the Central Coast and Southern Vietnam: Suối Cát (Khánh Hòa) 113.6mm, Công Hải (Ninh Thuận) 188.5mm, Phước Hòa (Ninh Thuận) 118.0mm, Vĩnh An (Đồng Nai) 112.2mm, Phước Vinh (Tây Ninh) 100.6mm, Trị An (Đồng Nai) 115.1mm, …
The Central Highlands also started having rain at the beginning of May 2023.
On 12-May there was a new spell of the cool Northeasterly Wind. It is clouds, rain and thunderstorms in most of Vietnam. The temperatures turned pleasant in most of the country.
The Central Coast seemed to have more rain. Recorded rainfall in Quang Nam from 14:00 to 20:00 hours on 12-May: Câu Lâu 148.8mm, cầu Hương An 128mm, Duy Trung 97.4mm, Đại Hiệp95.4mm, Ái Nghĩa 77mm, …
And the rainy season seemed to have started in the Central Highlands and Southern Vietnam. Recorded rainfall from 13:00 to 20:00 hours on 13-May: Suối Tân (Khánh Hòa) 88.8mm, Chánh Hội (Vĩnh Long) 79.8mm, Thuận Hạnh (Đắk Nông) 64.4mm, Thạnh Trị (Sóc Trăng) 62.4mm,...
From 16-May there is a new heat strike across the North and Central Region of Vietnam with high temperatures from over 35oC to over 37oC. Southern Vietnam has entered the rainy season but the temperatures in several places remained above 36oC.
The sub-regional weather in Vietnam during the heat strike starting on 16-May 2023:
- Northeast: sun, isolated rain, 24-37oC;
- Northwest: sun, clouds, 22-33oC in Lai Chau, 24-37oC in Hoa Binh, Yen Bai and Dien Bien; 26-39oC in Lao Cai;
- Lowlands: light rain, moist air, cloud, 26-38oC;
- The North of the Central Coast: sun, 27-38oC;
- Central Coast from Quang Binh to Hue: sun, 30-40oC in Quang Binh, 27-39oC in Quang Tri, 27-37oC in Hue;
- Central Coast from Da Nang to Quang Ngai: 27-35oC in Da Nang, 27-37oC in the others;
- Central Coast from Tuy Hoa to Phan Rang: sun, rain, 27-37oC;
- Phan Thiet: rain, 27-35oC;
- Central Highlands: rain, 22-34oC;
- East of Southern Vietnam (Ho Chi Minh, Tay Ninh, Binh Duong, Binh Phuoc, Dong Nai): rain, 27-37oC;
- West of Southern Vietnam (Mekong Delta): 26l-33oC.
On 23-May there was a cool air mass moving southwards. This cool air mass met the high-temperature air troughs along the latitudes of 22-23oC and kept on pushing the hot air southward which caused rain in various regions in Vietnam putting an end to the ongoing heat strike in several regions. Still, some places were not affected and the temperatures remained high: Mường Lay (Điện Biên) 38.5oC, Mường La (Sơn La) 41.0oC, Tương Dương (Nghệ An) 38.1oC, Sơn Hòa (Phú Yên) 38.7oC…
The sub-regional weather in Vietnam after the arrival of the cool air mass on 23-May:
- Northeast: sun, clouds, rain, 24-32oC;
- Northwest: sun, clouds, rain, 24-32oC in Hoa Binh, Yen Bai, Lai Chau, 24-34oC in Lao Cai, Dien Bien, Son La;
- Lowlands: breezes, clouds, sun, rain, 26-33oC;
- The North of the Central Coast: sun, clouds, rain, 26-33oC;
- Central Coast from Quang Binh to Hue: sun, clouds, rain, 26-35oC in Quang Binh, 26-33/32oC in Quang Tri, Hue;
- Central Coast from Da Nang to Quang Ngai: sun, clouds, rain, 26-34oC;
- Central Coast from Tuy Hoa to Phan Rang: sun, rain, 26-34oC;
- Phan Thiet: sun, clouds, rain, 26-34oC;
- Central Highlands: rain, 21-32oC;
- East of Southern Vietnam (Ho Chi Minh, Tay Ninh, Binh Duong, Binh Phuoc, Dong Nai): sun, clouds, rain, 27-34oC;
- West of Southern Vietnam (Mekong Delta): sun, clouds, rain, 25-33oC.
