Not unlike the north central and northeastern portions of the United States, weather in Beijing can be described in general as being a humid continental climate. This type of climate is quite common in temperate regions over large land masses. Usually humid continental climates receive their weather as a result of being sandwiched between tropical and polar air masses.
The winter season begins in late October and ends in March. Beijing lies roughly on the same latitude as Philadelphia, Denver and San Francisco. This means that winters are substantially cold with high temperatures hovering not far above freezing and low temperatures close to 17 degrees Fahrenheit (-8C) on average. The lowest ever recorded temperature in the city was -16F (-27C). Winter is often a windy season as well as being dry and is greatly affected by air masses from Siberia that move south across the Mongolian Plateau. January is on average the coldest month, and precipitation during the winter is often less than a centimeter.
Spring in Beijing is short, beginning in April and ending in May. Like winter, spring remains a dry season and is characterized by cold, high winds and sandstorms (caused by a combination of dry and hot air and high winds in the northern desert regions), especially in May. May also generally has more precipitation than in April. On average, temperatures change considerably during the spring with April having highs of 67F (19C) and May highs of 78F (25C). Precipitation during this season averages 1cm in April and rises to 3 by the end of May.
The Beijing summer begins in June, reaches its peak in July and ends in August. Summer is also the season that witnesses the most precipitation, with June averaging 7cm, July averaging 22cm and August 17cm. Summer in Beijing tends to be a hot, humid affair and temperatures throughout the season average 85F (29C) with July regularly claiming the highest temperatures. The highest temperature ever recorded in the city was 107F (42C). Incidentally, summer is also the height of the tourist season.
Autumn is generally considered to be the most pleasant season of the year. Not unlike New England, temperatures finally begin to fade after the often stifling cloud cover and humidity of summer. The season begins in September and ends in October. Precipitation drops off a great deal during this time with an average of only 5cm in September and just 1 in October. Average high temperatures in September is 78F (25C) and 66F (18C) in October.
