Kalasin's weather is characterized by a long hot season that lasts from March to June, with temperatures often reaching above 39°C. The summer months of April and May are particularly sweltering, with average highs around 30°C. A brief respite comes in July and August, but temperatures remain high, only dipping slightly in the evenings. As the year cools down, October and November bring more pleasant temperatures, ranging from 20-35°C, while December marks the start of a cooler period, with temperatures often dropping below 20°C.