Thailand will officially enter summer next Friday, with temperatures expected to be slightly lower than last year, the weather service said.

This year's summer will last from Feb 28 to mid-May, the Meteorological Department said on Friday.

There would be more moderate temperatures due to a cooler La Niña, which may help reduce heat and bring rainfall up to 20% above average during the three-month period. However, summer rain is likely to be brief and limited to certain areas.

According to the forecaster, this summer is expected to see temperatures between 35°C and 36°C, which is slightly lower than last year's average of 37.5°C.

The department warned that 14 provinces in the northern and northeastern regions should brace for extreme heat, with temperatures potentially exceeding 42°C in April, when summer typically reaches its peak.

The provinces expected to experience extreme heat are:

•     Chaiyaphum
•     Chiang Mai
•     Khon Kaen
•     Lampang
•     Lamphun
•     Loei
•     Mae Hong Son
•     Nong Bua Lamphu
•     Nong Khai
•     Phitsanulok
•     Sukhothai
•     Tak
•     Udon Thani
•     Uttaradit