The best months to visit Bulgaria are September and October. See monthly temperatures, rainfall and rain days (1991–2020 averages) to plan your trip.
Average daytime high and monthly rainfall in Bulgaria: January 6°C / 41mm; February 13°C / 39mm; March 14°C / 56mm; April 19°C / 60mm; May 20°C / 70mm; June 29°C / 62mm; July 31°C / 53mm; August 30°C / 36mm; September 24°C / 36mm; October 20°C / 49mm; November 10°C / 37mm; December 6°C / 46mm.