The Ultimate 6-days itinerary to Prague

1. The Basics

Weather

Prague experiences a temperate climate. Summers (June to August) are generally warm with average temperatures around 20-25ª (68-77ªF). Winters (December to February) are cold, with temperatures dropping below freezing and ocassional snowfall. Spring (March to May) and autum (September to November) bring milder temperatures.

Also, the distribution of rainfall is relatively balanced throughout the seasons, with a slight increase during the summer months. 

I recommend going in autumn, but do not leave the trip for the end of November. This way, you will avoid the big crowds of tourists (who usually go in summer) and the heavier rains, and you wont have to endure the cold temperatures and winter snowfalls; besides, the city is scenery beautiful at this time of the year!