Hengyang sits in sub-tropic area and therefore enjoys a humid monsoon climate. Its yearly average temperature goes between 17.2―18.1℃. The frost-free period lasts 281―297 days. Yearly hours of sunshine is 1583.7―1753.8, which is agreeable to many kinds of crops. The yearly rainfall is around 1200―1400 mm, most of which happens between April and September, a period which is important to the staple crops.  

Hours of Sunshine:The yearly gross quantity of sunlight radiation heat of this area is 100.49 to 106.76 calories per square centimeter. July`s radiation is the strongest with the average of 14.94 calories per square centimeter, taking up to 14.45% of the yearly total. February is the slightest month, taking only 4.68% of the yearly total. The average hours of sunshine goes between 1583.7 and 1753.8 hours. The sunshine hours extends from February to July mounting to 256.3 even to 277.9 hours.  

Temperature:  

Hengyang sits in sub-tropic area and therefore enjoys a humid monsoon climate. Its yearly average temperature goes between 17.2―18.1℃. The temperature hits the bottom rock in January with the average of 5--6℃. While July witnesses the highest temperature: 29--30℃. The annual range is between 23.5―24.6℃ while the extreme daily range is 9.4℃. The highest temperature of year is 39.6―41.3℃, while the lowest degree is －6.6 to －10.3 ℃.  

Rainfall:Hengyang has ample rain. The whole rain days are 156 to 171. the yearly average rainfall is 1329.8 mm. The concentration period of rainfall is in May with the amount of 193.9 to 212.1 mm. Stormy rains to 50 mm/day usually appear in May to August, and the biggest daily rainfall amount possible can reach 217.4 mm. Sometimes there may be not even a drizzle for a solid month. The biggest extreme case is that there was no rain for 70successive days, which happened in Hengdong in 1963.