May is summer in Northern Vietnam, the dry and hot season in the Central Coast, is in between the dry season and rainy season in the Central Highlands, and in Southern Vietnam.
General Weather Patterns in Vietnam in May
In Northern Vietnam, the Northwest may have areas under impact of the foehn wind and may have high temperatures. There may be torrential rain in both the Northwest and Northeast of Vietnam which could make places temporarily flooded.
The Central Coast of Vietnam often has high temperatures and strong sun in May. The region is under heat strikes most of the time due to foehn wind and due to growing hot air troughs over the northwest and west of Vietnam.
The first half of May the temperatures are still high in Southern Vietnam (34oC to above 35oC) and in parts of the Central Highlands. More daily short-lived rains are found in Southern Vietnam and in the Central Highlands from the second half of May which make the temperatures slightly lower.
Thanks to high altitudes the Central Highlands may suffer warm temperatures mostly at mid day. It is mostly chilly or pleasant in the morning, late afternoon and in the evening. The South of Vietnam is hot until more daily short-lived rain come from mid May which makes temperatures more tolerable.
Monsoons in Vietnam in May
Vietnam has a tropical monsoon climate and the monsoons do have great impacts on the weather in different regions in the country. In May, Vietnam is under the influence of possibly two or three monsoons:
- The Northeasterly Monsoon: The wind, if present in May, mostly originates from Tibet. In May, the Northeasterly Wind is substantially weaker than in the winter time. This wind often causes dry weather with extremely pleasant temperatures. The wind may blows weakly in Northern Vietnam in the first week or 10 days of May. But it may be possible that the wind won’t be present at all.
- The Southeasterly Monsoon: This is the predominant summer monsoon in Northern Vietnam. In May the wind is mostly getting stronger. This wind is humid as it blows inland from the sea. The wind could be in conflict with the Northeasterly Monsoon which causes torrential rain, hails... Else, the wind makes the temperatures more of pleasant levels.
- The Southwesterly Monsoon: This monsoon causes rain in Southern Vietnam and in the Central Highlands of Vietnam. Due to the foehn effect, this same wind causes dry and high temperatures in the Central Coast and in the far northwest of Vietnam (Dien Bien, Son La, part of Hoa Binh and Lai Chau). In May, the Southwesterly Wind gets more active.
Adventure Travel, nature tours, bird watching tours in Vietnam in May
May is generally not a good time for adventure tours, bird watching tours in Vietnam. This is because of the high temperatures which are not suitable for active holidays and because of rain which makes forest trails, nature trails muddy for bike tours or trekking tours. The sun is quite strong mostly which enervates us quickly. May is the time that most migratory bird species have left national parks in Vietnam, and bird parks in the country are not busy with wildlife as during autumn, winter and spring time (October through February or March).
Since the Northeasterly Monsoon is too weak or not present at all, those who plan to travel to Vietnam’s offshore islands like Ly Son, Con Dao and Phu Quoc should enjoy calm sea. May is among the best time to make adventure holidays ro beach vacations to these islands: mild sunshine, lovely temperatures, calm sea. All sea exploration tours, water sport activities and boat tours should operate smoothly as planned.
Below is Weather in Vietnam in May 2023 Monitored by AdventureGreen
First week of May, 2023
In first few days of May 2023, there was a weak spell of the cool Northeasterly Wind (Winter Monsoon) which cause pleasant temperatures in most of Northern Vietnam and part of the Central Coast of Vietnam. The South of Vietnam had been undergoing a bad heat strike with daily temperatures surpassing 37-38oC in several places including the Mekong Delta.
Due to growing hot temperature air troughs the heat strike had impact in most of Vietnam in the last couple of days of the first week of May 2023 with most places above 35-36oc. During the heat strike several places had daily temperatures surpassing 40-43oC ! The heat strike lasted for only two days in Northern Vietnam.
At the end of the first week, there was a tropical depression at sea, 400km east southeast of the Song Tu Tay (Truong Sa Islands, Spratly Islands of Vietnam).
The highest temperatures during the heat strike were found at : 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.
Second week of May, 2023
The second week started with a new spell of the cool Northeasterly Wind hitting Northern Vietnam and part of the Central Coast of Vietnam. The cool wind cause torrential rain in Northern Vietnam.
The cool wind blew when the hot air troughs had been causing a heat strikes across Vietnam which result in extreme weather : strong winds brought down several houses in Nghe An Province ; strong gusts of wind capsized and sunken several boats at sea off the coast of Quang Binh, Quang Tri and Thua Thien Hue Provinces.
In part of the Central Highlands and Southern Vietnam, there was torrential rain at the beginning of the second week of May 2023 which cause streets in several places flooded in Ho Chi Minh City, Dong Nai and Binh Duong.
The regional weather was as follows:
- Northeast : clouds, rain, 18-28oC ;
- Northwest : rain, 20-30oC ;
- North of the Central Coast : rain, 21-31oC ;
- Mid Central Coast to the north of Hai Van : mostly rain, clouds, 26-32oC ;
- Mid Central Coast to the south of Hai Van : some clouds, rain mostly, 26-33oC ;
- South Central Coast (Quy Nhon – Nha Trang): rain, clouds, 26-33oC ;
- South Central Coast ( Phan Rang-Thap Cham to Phan Thiet : rain, 26-34oC ;
- Central Highlands : clouds, rain mostly, 21-32oC ;
- Southern Vietnam: rain, 26-33oC.
On 12-May there was another spell of the Northeasterly Wind affecting the Northeast of Vietnam, North of the Central Coast and part of the Mid of the Central Coast. The cool wind causes rain and thunderstorms in the affected areas.
Rainfalls recorded from 19:00 on 11-May to 03:00 on 12-May : Yên Thủy (Hòa Bình) 85.6mm, Tà Tổng (Lai Châu) 73mm, Đồng Khê (Yên Bái) 87.4mm, Thọ Dân (Thanh Hóa) 151.6mm, Châu Nga (Nghệ An) 79mm,…
Rainfalls recorded in the period of 00:00 to 05:00 hour on 12-May : Nùng Nàng (Lai Châu) 98mm, Nậm Hàng 3 (Lai Châu) 80,4mm, Mường Tùng ( Điện Biên) 93mm...
In Central Highlands and Southern Vietnam, more torrential rain confirms that the rainy season had started already and temperatures turned pleasant in all over Vietnam.
Third week of May, 2023
The third week of May 2023 started off with growing high-temperature air troughs in the atmosphere over the west of Vietnam. The North and the Central Coast had more sun and higher temperatures. The Central Highlands and Southern Vietnam had entered the rainy season and the temperatures turned more tolerable.
The regional weather was as follows:
- Northeast : sun, clouds, isolated rain, 24-35oC ;
- Northwest : clouds, sun, some isolated rain, 24-37oC in Hoa Binh and Yen Bai, Lao Cai ; 22-36oC in Dien Bien, Son La ; 22-32oC Lai Chau ;
- Lowlands in Northern Vietnam : clouds, sun, 26-38oC ;
- North of the Central Coast : sun, clouds, 27-37oC ;
- Mid Central Coast to the north of Hai Van : sun, clouds , isolated rain, 27-37oC in Quang Tri, Hue ; 27-39oC in Quang Binh;
- Mid Central Coast to the south of Hai Van : clouds, sun, isolated rain, 27-37oC ;
- South Central Coast (Quy Nhon – Nha Trang): clouds, sun, rain, 28-36oC ;
- South Central Coast ( Phan Rang-Thap Cham to Phan Thiet : sun, clouds, rain, 27-37oC in Phan Rang, 27-35oC in Phan Thiet;
- Central Highlands : showers, sun, clouds, 22-33oC ;
- Southern Vietnam: showers, sun, clouds, 26-34oC in the Mekong Delta, 27-36oC in Ho Chi Minh, Dong Nai, Binh Duong, Binh Phuoc, Tay Ninh.
Fourth week and last days of May, 2023
The heat strike across different regions in Vietnam continued into the fourth week of May 2023 with highest temperatures recorded in the North and Central Coast. The places with highest temperatures on 22-May : Mường La (Sơn La) 42.3oC, Phù Yên (Son La) 42.2oC, Mai Châu (Hòa Bình) 42.3oC, Phố Ràng (Lào Cai) 41.2oC, Bắc Mê (Hà Giang) 42.6oC, Bảo Lạc (Cao Bằng) 41.4oC, Hồi Xuân (Thanh Hóa) 42.5oC, Tây Hiếu (Nghệ An) 41.6oC
On 23-May there was a cold air mass (weak spell of Northeasterly Wind) which met and pressed the air troughs on the latitude of 22-23o southwards which caused rain in several regions and which put an end to the heat strike.
The Central Highlands and South of Vietnam have definitely entered the rainy season with torrential daily rain that caused temporary floods in various cities.
Regional weather in Vietnam after the arrival of the cool air mass on 23-May-2023
- Northeast : sun, clouds, rain, 24-32oC mostly;
- Northwest : sun, 23-36oC in Lao Cai, Son La, Dien Bien ; 24-32oC in Hoa Binh, Yen Bai and part of Lai Chau ;
- Lowlands in Northern Vietnam : sun, clouds mostly, rain, breezes, 26-33oC ;
- North of the Central Coast : clouds, sun, showers, 26-33oC mostly;
- Mid Central Coast to the north of Hai Van : sun, clouds, rain, 26-39oC in Quang Binh ; 26-36oC in other places;
- Mid Central Coast to the south of Hai Van : clouds, showers, 26-37oC ;
- South Central Coast (Quy Nhon – Nha Trang): sun, rain, 26-37oC ;
- South Central Coast ( Phan Rang-Thap Cham to Phan Thiet : sun, clouds, rain, 26-37oC in Phan Rang, 26-34oC in Phan Thiet;
- Central Highlands : clouds, rain, 22-33oC ;
- East of Southern Vietnam (Tay Ninh, Ho Chi Minh City, Binh Duong, Binh Phuoc, Dong Nai) : sun, clouds, rain, 27-36oC .
- West of Southern Vietnam (Mekong Delta) : clouds, rain, 26-33oC.
From 29-May till the end of the month, there was a heat strike again across the North and the Central Region. Highest recorded temperatures on 30-May in Vietnam: Mường Tè (Lai Châu) 39.2oC, Mường Lay (Điện Biên) 39.5oC, Mường La (Sơn La) 42.7oC, Phố Ràng (Lào Cai) 38.1oC, Bắc Mê (Hà Giang) 40.3oC, Chợ Rã (Bắc Kạn) 38.4oC, Bảo Lạc (Cao Bằng) 40.6oC.
The Central Highlands and South of Vietnam are in the rainy season now with daily-torrential rain which make temperatures pleasant in these two regions.
Regional weather in Vietnam in the last days of May 2023
- Northeast : sun, 26-39oC;
- Northwest : sun, clouds, 22-34oC in Lai Chau ; 28-39oC in Lao Cai, Son La, Dien Bien ; 27-37oC in Hoa Binh, Yen Bai ;
- Lowlands in Northern Vietnam : sun, 28-38oC ;
- North of the Central Coast : sun, 28-38oC mostly;
- Mid Central Coast to the north of Hai Van : sun, 27-38oC ;
- Mid Central Coast to the south of Hai Van : clouds, showers, 26-36oC ;
- South Central Coast (Quy Nhon – Nha Trang): sun, rain, 26-35oC ;
- South Central Coast ( Phan Rang-Thap Cham to Phan Thiet : sun, clouds, rain, 26-37oC in Phan Rang, 26-34oC in Phan Thiet;
- Central Highlands : clouds, rain, 21-30oC ;
- East of Southern Vietnam (Tay Ninh, Ho Chi Minh City, Binh Duong, Binh Phuoc, Dong Nai) : clouds, rain, 26-33oC .
- West of Southern Vietnam (Mekong Delta) : clouds, rain, 25-30oC mostly, 26-32oC in An Giang.
