Lu'an is located in the transit area of subtropical and temperate zones with two remarkable characteristics: The first is that, it has a monsoon climate with four distinct seasons spring, summer, autumn and winter. The winter is very cold and summer is very hot. The second is that its climate is mild with moderate rainfall, sufficient sunshine, long frost-free term and good heat condition.
The annual total sun radiance is 110 to 125 kilocalorie per square centimeters, equaling to the energy of 730 million kilocalorie to 830 million kilocalorie received by per mu land. The distribution of sun radiance to the north or to the plain area is more than that to the south or to the mountainous area. The annual average temperature is 14.6 to 15.6 Celsius centigrade with much bigger temperature difference among different seasons. The hottest month is July, averaging 27,2 to 28.4 Celsius centigrade with extreme hot temperature of 43.3 Celsius centigrade. The coldest month is January, averaging 1.4 Celsius centigrade with the coldest temperature between 7 and 12 Celsius centigrade for years. The average frost days are between 211 and 228. The first frost occurs around 2nd to 11st of November and the last frost occurs around 27th of March to 3rd of April. The frost-free season in mountainous area is shorter, only 190 days or so in the area of 500 meters above sea level. In mountainous area, spring comes late and autumn ends earlier. Frostbite often occurs in spring and autumn seasons. The annual average rainfall is 900 to 1600 mm with evaporation of 1300 to 1500 mm. The raining season falls in late June and early July and lasts for about 20 days with average rainfall of more than 200 mm for years.
Lu'an has different varieties of topographical conditions. It has mountains, hilly lands and plains distributed in terraced terrain with rivers, basins and lakes dotted in between. The whole city can be divided into four different pieces of topographic lands: Northern Slope of Dabies Mountain, Hilly Land and Hillocky Land between Changjian and Huaihe River.