Hefei features a humid subtropical climate (Köppen Cfa) with four distinct seasons. Hefei's annual average temperature is 15.8 °C (60.4 °F). Its annual precipitation is just under 1,000 millimetres (39 in), being heavier from May through August. Winters are damp and cold, with January lows dipping just below freezing and a January average of 2.6 °C (36.7 °F). The city sees irregular snowfalls that rarely turn significant. Springs are generally relatively pleasant if somewhat erratic. Hefei’s summers are oppressively hot and humid, with a July average of 28.1 °C (82.6 °F). In the months of June, July, August, and often September, daily temperatures can reach or surpass 37 °C (99 °F) with high humidity levels being the norm. Fall in Hefei sees a gradual cooling and drying.
Usually in May and June, air quality in Hefei diminishes. The city is blanketed by a sweet-smelling smog caused by the smoke generated as farmers outside the city burn their fields in preparation for planting the next crop
