With January averaging 69.2 °F (20.7 °C), winter features warm temperatures; cool air usually settles after the passage of a cold front, which produces much of the little amount of rainfall. Lows sometimes fall to or below 50 °F (10 °C), with an average 3 such occurrences annually,[1] but rarely 40 °F (4 °C); from 1981 to 2010, temperatures reached that level in only eight calendar years.[2] Highs generally reach 70 °F (21 °C) or higher, and fail to do so on only an average of 12 days annually.