In short: the Czech Republic has a temperate continental climate. Compared to the summers in the UK, the summers in the Czech Republic are warmer and more stable.
Climate Czech Republic
The Czech Republic has a temperate continental climate. The temperate is mainly in the summers. They are warm, but not extreme. In the capital Prague, the average temperature in the middle of summer is 23°C. In winter it is cold. In January, the coldest month, the mercury rarely rises above zero. Because the ocean is fairly close, there is plenty of winter fun to be had in winter due to the moist, cold air. There are more than enough winter sports options in the Bohemian Forest and the Giant Mountains.