The summer months of June - August can get very hot and humid, therefore the best times to visit are the spring and autumn months of April & May, and mid-September and October , when the temperatures are more favourable.
Perugia is very popular in July when the International Jazz festival is held so this can be an expensive time to visit.
November is the wettest month with around 4 inches (100mm) and July is the driest month with around 1 to 2 inch (25 to 50mm)
NOTE: Because Perugia is a hill town it can be very cold in winter because of the winds - it can also snow. It can also be a little chilly at night even in the summer.
Spring months: March, April, May
Summer months: June, July, August
Autumn months: September, October, November
Winter months: December, January, February