sān fú
three periods forming the hottest periods of summer, from mid-July to mid-August, namely: 初伏 (mid-July), 中伏 (late July to early August), 末伏 (mid-August)
zhōng fú
last ten days of July and first ten days of August, the second of 三伏 sān fú, three hottest periods of the year
chū fú
middle ten days of July, the first of 三伏 sān fú, three hottest periods of the year
mò fú
middle ten days of August, the last of 三伏 sān fú, three hottest periods of the year