Jinan is located in the mid-latitude zone, influenced by solar radiation, atmospheric circulation and geographical environment, and belongs to the warm temperate and semi-humid monsoon climate.
It is characterized by obvious monsoon, four distinct seasons, drought and little rain in spring, warm and rainy in summer, cool and dry in autumn and cold and little snow in winter.
The annual average temperature is 13.8℃, the frost-free period is 178 days, the highest temperature is 42.5℃ (1July 24th, 955), and the lowest temperature is-0/9.7℃ (1953 65438+/).
The monthly average maximum temperature is 27.2℃ (July) and the monthly average minimum temperature is -3.2℃(65438+ 10 month).
The average annual precipitation is 685 mm.
The annual sunshine hours are 1870.9 hours (2009).
In winter, the Mongolian high is formed in the northern part of the Asian continent, and Jinan is controlled by the polar continental air mass and is often attacked by cold air from the north. The weather is cold and sunny, with less rain and snow and more northerly winds.
In summer, influenced by tropical and subtropical ocean air masses, warm and humid air currents prevail in the ocean, with hot weather, abundant rainfall, abundant sunshine and southerly winds.
Spring and autumn are the transitional seasons from winter to summer and from summer to winter, and the wind direction is changeable.
In a year, Jinan is controlled by different atmospheric circulation in different seasons, which constitutes a distinct climate in spring, summer, autumn and winter.
The winter duration in Jinan is 136 ~ 157 days, generally from early October to late March of the following year. Summer is 105 ~ 120 days, generally from late May to early September; Spring and autumn are the shortest, less than two months.
In addition, the terrain surrounded by mountains on three sides makes it difficult for water vapor and hot air to return and gather, which is more than the summer precipitation in general northern cities.