The best months to visit Thailand are December and January. See monthly temperatures, rainfall and rain days (1991–2020 averages) to plan your trip.
Average daytime high and monthly rainfall in Thailand: January 32°C / 15mm; February 35°C / 14mm; March 37°C / 40mm; April 40°C / 71mm; May 36°C / 135mm; June 35°C / 131mm; July 33°C / 137mm; August 33°C / 147mm; September 33°C / 241mm; October 32°C / 194mm; November 32°C / 42mm; December 30°C / 10mm.