Autumn: Prague looks full of life as the leaves tend to change their color from bright green into yellow, orange and red during autumn season which lasts from September to November.
Winter: Winters span from December to February. During coldest months in Prague, mountains are covered with heavy snow and temperature often drops below 0 degrees. This can be a good time if you are looking forward to avoid crowd. Winter is when the locals take back the city and it is an off season. Tourists are still here but nowhere near the amount that buzz around in the summers.
Summer: June, July and August are warmest months and may result in storm and rains. The nice thing about summer in Prague is that all the old castles and churches provide a cool break from the hot sun. There are benches all over the city for you to just sit and watch the people walk by. There are lawns, parks and even the King's Garden for you to just lie down and rest your cobblestone weary feet. Please expect crowds as this is a high season.
Spring: Spring In Prague may show whimsical behaviour as snow begins to melt and temperature gradually ascends during March, April and May.
The best time to visit Prague is during the summer (June to August) when the temperatures are generally pleasantly warm, though rain is not unheard of at any time of year and late Spring is very wet indeed.