 This trend continues through late autumn and winter, with a marked drop in precipitation beginning in April which coincides with a gradual rise in temperature into late spring and summer.There is significant variation in rainfall throughout the year, with December and January receiving a mix of rainfall and snow, averaging 9.06 and 7.94 inches respectively.Rainfall during summer is, on average, less than half an inch each month with July receiving the lowest monthly average precipitation of the year at .07 inches.