The best time to visit Mahasarakham is November to early February, the cool dry season for Isan, when daytime temperatures sit between 25 and 30°C and the mornings can be pleasantly cool. This is the part of the year when the rice harvest is finishing in the surrounding paddies and village festivals are most frequent.
March to May is the hot dry season, when temperatures push above 35°C and the air over central Isan becomes hazy from agricultural burning. The university summer break in April and May empties the town of students, and the food street and bar scene are noticeably quieter. June to October is the wet season — short, heavy afternoon storms rather than sustained rain, plenty of mosquitos, and lush green paddies. Avoid the week of Songkran (around 13–15 April), when long-distance buses are booked solid and prices spike, and Loy Krathong in November, when the candles on Bueng Bon make for a quiet but pretty evening if you happen to be in town.