Spring (April – May)
Spring is the season most guidebooks quietly agree on, and for good reason. By late April the parks and riverbanks are green again, the big tour-bus crowds from summer haven't arrived yet, and hotel rates are still reasonable. Expect cool mornings and mild afternoons, with a genuine chance of rain — pack a layer and something waterproof rather than trusting a forecast more than a day or two out.
The one date worth planning around is Easter: the Old Town Square gets a market and a real crowd surge, similar to Christmas but smaller. If you want spring without the Easter spike, aim for the second half of April or all of May.
Summer (June – August)
This is peak season, and it's peak for a reason: long daylight hours, terraces open until late, and the warmest weather of the year (typically low-to-mid 20s°C, with the occasional hot spell pushing past 30°C). It's also when Prague is busiest and priciest — Charles Bridge and the Old Town Square can feel genuinely packed by mid-morning.
If you're travelling in summer, the trade is worth making by starting early: the castle grounds and bridge are dramatically quieter before 9am, and you get the golden light for photos as a bonus.
Autumn (September – October)
Autumn is spring's quieter sibling. September in particular is a favourite among people who've been to Prague before: warm days, cooling evenings, fewer school-holiday crowds, and the city's parks turning gold by October. Rain becomes more likely as the season goes on, and by late October the evenings are properly cold.
Winter (November – February)
Winter splits into two very different experiences. Late November through early January is Christmas-market season — Old Town Square and Wenceslas Square fill with wooden stalls, mulled wine (svařák), and a large lit tree, and the atmosphere is genuinely worth braving the cold for. January and February, by contrast, are the quiet months: short, grey days, temperatures that regularly sit around or below freezing, and the cheapest flights and hotel rates of the year.
Snow is possible but not guaranteed in any given week, so don't plan a trip purely around white rooftops — treat it as a pleasant surprise if it happens.
Our take
For a first visit with normal flexibility, late April to May or September gives you the best ratio of good weather to manageable crowds. If your dates are fixed by school holidays, summer is still absolutely worth it — just start your sightseeing early in the day. And if you've already seen the highlights once, a December trip for the Christmas markets is one of the most atmospheric ways to see the city again.