Roi Et experiences a hot and humid climate throughout the year, with temperatures rarely dropping below 10°C. The coolest months are January and December, with average temperatures ranging from 22-23°C, while the hottest months are February to April and June to August, with temperatures averaging around 29-30°C. May and September are transitional periods, with temperatures gradually decreasing or increasing by a few degrees. Nights can be quite cool during the winter months, but days remain warm and sunny year-round. The temperature variations throughout the day are significant, with daytime highs often reaching 38-40°C in the peak summer months.