the atlanta metro area has a humid subtropical climate with four seasons, although summer is the longest. january daily lows average from north to south, and highs range from , but often reach well above or below this average. there is an average annual snowfall of about , falling mostly from december through march, though there was snow north of the city on april 3, 1987. snow flurries are actually common during the winter months when there is an especially deep trough in the jet stream. these events usually do not amount to more than a slight dusting and therefore go unrecognized in most weather summaries. summers, by contrast, are long and consistently hot and humid, with july mornings averaging and afternoons averaging , slight breezes, and typically a 20–40% chance of afternoon thunderstorms. during the summer afternoon thunderstorms, temperatures may suddenly drop to 70–77 degrees with locally heavy rainfall. average annual rainfall is about , with late winter and early spring (as well as july) being the wettest and fall (especially october) being the driest.