According to the weather forecast from the National Center for Hydro-Meteorological Forecasting, the North will have scattered showers and thunderstorms in the evening and night of May 21, sunny days, and hot weather in some places.
From the night of May 22 to May 23, in the Northern region, there will be moderate rain, heavy rain and thunderstorms, locally very heavy rain with common rainfall of 40-90mm, locally over 150mm.
Weather forecast for the Central region in the evening and night of May 21 has scattered showers and thunderstorms, the South Central region has scattered showers and thunderstorms in the afternoon and evening; sunny day, some places are hot, especially the area from Thanh Hoa to Phu Yen has hot weather, some places are very hot.
Weather forecast for the Central Highlands and the South has showers and thunderstorms in some places, especially in the afternoon and evening there is rain, moderate rain and thunderstorms, locally heavy rain in some places.
People and tourists need to be on guard during thunderstorms with the possibility of tornadoes, lightning, hail and strong gusts of wind.

Weather forecast for tomorrow in Hanoi
Lowest temperature: 26-28 degrees Celsius
Highest temperature: 33-35 degrees Celsius, some places above 35 degrees Celsius
Cloudy, scattered showers and thunderstorms at night; sunny during the day, some places are hot. Male wind level 2-3.
Weather forecast for tomorrow in the Northwest region
Lowest temperature: 24-27 degrees Celsius; Northwest region 21-24 degrees Celsius, some places below 21 degrees Celsius
Highest temperature: 32-35 degrees Celsius, some places above 36 degrees Celsius
State: Cloudy, showers and thunderstorms in some places in the evening and at night; sunny during the day, some places are hot. Light wind. During thunderstorms, there is a possibility of tornadoes, lightning, hail and strong gusts of wind.
Weather forecast for tomorrow in the Northeast region
Lowest temperature: 25-28 degrees Celsius; mountainous areas below 24 degrees Celsius
Highest temperature: 32-35 degrees Celsius, some places above 35 degrees Celsius
Cloudy, showers and thunderstorms in some places in the evening and at night; sunny during the day, some places are hot. Southeast to south wind level 2-3. During thunderstorms, there is a possibility of tornadoes, lightning, hail and strong gusts of wind.
Weather forecast for tomorrow in the area from Thanh Hoa to Thua Thien Hue
Lowest temperature: 25-28 degrees Celsius
Highest temperature: 34-37 degrees Celsius, some places above 37 degrees Celsius
State: Cloudy, showers and thunderstorms in some places in the evening and at night; hot sunny day, some places are very hot. Light wind. During thunderstorms, there is a possibility of tornadoes, lightning, hail and strong gusts of wind.
Weather forecast for tomorrow in the area from Da Nang to Binh Thuan
Lowest temperature: 25-28 degrees Celsius
Highest temperature: North 34-36 degrees Celsius, some places above 37 degrees Celsius; South 32-35 degrees Celsius
North: Cloudy, showers and thunderstorms in some places in the evening and at night; hot sunny during the day, some places are very hot
South: There will be showers and thunderstorms in some places; in the afternoon and evening, there will be scattered showers and thunderstorms, locally moderate rain, heavy rain
Light wind. During thunderstorms, there is a possibility of tornadoes, lightning, hail and strong gusts of wind.
Weather forecast for tomorrow in the Central Highlands
Lowest temperature: 20-23 degrees Celsius
Highest temperature: 29-32 degrees Celsius, some places above 32 degrees Celsius
Cloudy, with showers and thunderstorms in some places; in the afternoon and evening, there will be rain, moderate rain and scattered thunderstorms, with some places having heavy rain. Light wind. During thunderstorms, there is a possibility of tornadoes, lightning, hail and strong gusts of wind.
Weather forecast for tomorrow in the Southern region
Lowest temperature: 24-27 degrees Celsius
Highest temperature: 31-34 degrees Celsius, some places above 34 degrees Celsius
Cloudy, with showers and thunderstorms in some places; in the afternoon and evening, there will be rain, moderate rain and scattered thunderstorms, with some places having heavy rain. Light wind. During thunderstorms, there is a possibility of tornadoes, lightning, hail and strong gusts of wind.