Czechoslovakia's central European location influences its climate. Although the continental weather systems that dominate Eastern Europe prevail throughout the country, western regions are frequently influenced by the maritime weather prevalent in Western Europe. When the systems to the north are weak, Mediterranean weather may occasionally brush southern parts of the country.

Winters are fairly cold, cloudy, and humid, although high humidity and cloud cover tend to be more prevalent in valleys and lower areas. Light rain or snow is frequent. The mountains are covered with snow from early November through April, and accumulations are deep in some places. Lower elevations rarely have more than fifteen centimeters of snow cover at a time.

Summers are usually pleasant. There is heavy rainfall, but it comes in sporadic showers, making for many warm, dry days with scattered cumulus clouds. Prevailing winds are westerly; they are usually light in summer (except during thunderstorms) and somewhat stronger in winter.

Average temperatures in Prague, which is representative of lowland cities in Bohemia and Moravia, range between about 1°C in January and about 19°C in July. Winters are chilly; summers have warm afternoons and cool evenings. In the eastern parts of the country, the temperature extremes are greater. Higher elevations, especially those with western exposures, usually have a narrower temperature range but on the average are considerably cooler. December, January, and February are the coldest months; June, July, and August are the warmest. Spring tends to start late, and autumn may come abruptly in middle or late September. At lower elevations, frosts are rare between the end of April and the beginning of October.

Rainfall varies widely between the plains and the upland areas. Parts of western Bohemia receive only forty centimeters of rainfall per year; some areas in the Vysoke Tatry average two meters. The average rainfall in the vicinity of Prague is fortyeight centimeters. Precipitation varies more than in other areas of Europe, which are often dominated by maritime weather systems; consequently, droughts and floods sometimes occur.

Despite the greater frequency of precipitation during the winter, more than twice as much precipitation, or about 38 percent, falls in the summer. The spring and autumn figures are about equal.

Data as of 1987