Under the Köppen classification, Atlanta has a humid subtropical climate (Cfa) with four distinct seasons and generous precipitation year-round, typical for the Upland South; the city is situated in USDA Plant Hardiness Zone 8a, with the northern and western suburbs, as well as part of Midtown transitioning to 7b. Summers are hot and humid, with temperatures somewhat moderated by the city’s elevation. Winters are cool but variable, occasionally susceptible to snowstorms even if in small quantities on several occasions, unlike the central and southern portions of the state. Warm air from the Gulf of Mexico can bring spring-like highs while strong Arctic air masses can push lows into the teens °F (−7 to −12 °C).
July averages 80.9 °F (27.2 °C), with high temperatures reaching 90 °F (32 °C) on an average of 47 days per year, though 100 °F (38 °C) readings are not seen most years. January averages 44.8 °F (7.1 °C), with temperatures in the suburbs slightly cooler due largely to the urban heat island effect. Lows at or below freezing can be expected 36 nights annually, but the last occurrence of temperatures below 10 °F (−12 °C) is January 6, 2014. Extremes range from −9 °F (−23 °C) on February 13, 1899 to 106 °F (41 °C) on June 30, 2012. Average dewpoints in the summer range from 63.7 °F (17.6 °C) in June to 67.8 °F (19.9 °C) in July.
Typical of the southeastern U.S., Atlanta receives abundant rainfall that is evenly distributed throughout the year, though spring and early fall are markedly drier. The average annual precipitation is 50.43 in (1,281 mm), while snowfall is typically light with a normal of 2.2 inches (5.6 cm) per winter. The heaviest single snowfall occurred on January 23, 1940, with around 10 inches (25 cm) of snow. However, ice storms usually cause more problems than snowfall does, the most severe occurring on January 7, 1973. Tornadoes are rare in the city itself, but the March 14, 2008 EF2 tornado damaged prominent structures in downtown Atlanta.