The department advised people to stay safe by keeping off unsecured buildings and being outdoors. Farmers should beware of crop damage.
In the South, there is a possibility of less rain.
The weather forecast for the next 24 hours is:
North: Hot weather during the day with thundershowers and gusty winds in 30 per cent of the area; temperature lows of 16-24 degrees and highs of 34-37 degrees Celsius.
Northeast: Thundershowers in 60 per cent of the area along with gusty winds and hail; temperature lows of 21-25 degrees and highs of 24-35 degrees.
Central region: Hot weather during the day with thundershowers in 20 per cent of the area along with gusty winds; temperature lows of 23-26 degrees and highs of 35-36 degrees.
East: Mostly cloudy with thundershowers in 20 per cent of the area along with gusty winds; temperature lows of 24-27 degrees, highs of 32-36 degrees; waves a metre high.
South (east coast): Partly cloudy with thundershowers in 10 per cent of the area; temperature lows of 21-26 degrees, highs of 32-35 degrees; waves a metre high.
South (west coast): Partly cloudy with thundershowers in 10 per cent of the area; temperature lows of 23-26 degrees, highs of 35-37 degrees; waves a metre high.
Bangkok and surrounding areas: Hot weather during the day with isolated rains; temperature lows of 25-27 degrees, highs of 32-37 degrees Celsius.