Dayton’s climate features warm, muggy summers and cold, dry winters, and is classified as a humid continental climate . Unless otherwise noted, all normal figures quoted within the text below are from the official climatology station, Dayton International Airport, at an elevation of 1,000 ft (304.8 m) about 10 mi (16 km) to the north of downtown Dayton, which lies within the valley of the Miami River; thus temperatures there are typically cooler than in downtown.
At the airport, monthly mean temperatures range from 27.5 °F (−2.5 °C) in January to 74.1 °F (23.4 °C) in July. The highest temperature ever recorded in Dayton was 108 °F (42 °C) on July 22, 1901, and the coldest was −28 °F (−33 °C) on February 13 during the Great Blizzard of 1899. On average, there are 14 days of 90 °F (32 °C)+ highs and 4.5 nights of sub-0 °F (−18 °C) lows annually. Snow is moderate, with a normal seasonal accumulation of 23.3 in (59 cm), usually occurring from November to March, occasionally April, and rarely October. Precipitation averages 41.1 inches (1,040 mm) annually, with total rainfall peaking in May.
Dayton is subject to severe weather typical of the Midwestern United States. Tornadoes are possible from the spring to the fall. Floods, blizzards, and severe thunderstorms can also occur.
Around midnight May 27–28, 2019, 14 tornadoes cut a path through the region, causing extensive property damage, but only one death. The tornadoes closed several streets, including portions of I-75 and North Dixie Street. 64,000 residents lost power and much of the region’s water supply was cut off. Although some of the tornadoes were only EF0 and remained on the ground for less than a mile, an EF4 tornado passed through the communities of Brookville, Trotwood, Dayton, Beavercreek, and Riverside.