Yunnan has a generally mild climate with pleasant and fair weather because of the province's location on south-facing mountain slopes, receiving the influence of both the Pacific and Indian oceans, and although the growing period is long, the rugged terrain provides little arable land. See Agriculture in Yunnan. Under the Köppen climate classification, much of the province lies within the subtropical highland (Köppen Cwb) or humid subtropical zone (Cwa), with mild to warm winters, and temperate summers, except in the almost tropical to truly tropical south, where temperatures regularly exceed 30 °C (86 °F) in the warmer half of the year.[44] In general, January average temperatures range from 8 to 17 °C (46 to 63 °F); July averages vary from 21 to 27 °C (70 to 81 °F).