Prague has a humid, continental climate, with warm summers and cold winters. Temperatures range from January's average daily high of 32°F (0°C) and low of 22°F (-4°C) to July's average daily high of 76°F (24.5°C) and low of 56°F (14°) Average annual rainfall is about 30 inches, distributed throughout the year. Humidity averages about 80 percent. During the winter months, high humidity makes the winter cold penetrating. Light to moderately heavy snow can be expected during January and February. Pollution can be severe during the winter months because of soft-burning coal and frequent temperature inversions. Reduced hours of daylight from November through March combined with smog and raw weather create a gloomy atmosphere. In fact, from mid-October when Daylight Savings Time ends until early April when it begins again, Czech law requires drivers to drive with their headlights on at all times.