Tucson experiences a desert climate, meaning that temperatures are high and rainfall is too low to sustain much vegetation at all. There are two major seasons, summer and winter, with three minor shoulder seasons: autumn, spring, and the monsoon.Early summer, particularly June, enjoys low humidity and clear skies, with daytime highs reaching above 100°F (38°C) and average overnight temperatures ranging between 66°F (19°C) and 85°F (29°C). In July and August, temperatures are much the same but it is much more humid and rain is very common, as this is the monsoon season.Flash floods are possible in late summer. Winters, between December and February, are mild, with average daytime highs between 40°F (4°C) and 68°F (20°C). The milder weather of winter is usually most pleasant for tourists.
