Birmingham has a humid subtropical climate , characterized by hot summers, mild winters, and abundant rainfall. January has a daily mean temperature of 44.7 °F (7.1 °C), and there is an average of 47 days annually with a low at or below freezing, and 1.2 where the high does not surpass freezing. July has a daily mean temperature of 81.5 °F (27.5 °C); highs reach or exceed 90 °F (32 °C) on 65 days per year and 100 °F (38 °C) on 2. Precipitation is relatively well-distributed throughout the year, with March the wettest month on average, and October the driest. Snow occasionally falls during winter, but many winters pass with no snow or only a trace. The most recent winter to report zero snowfall was 2019–2020, the first since 1936–1937. However, 10.3 inches (26.2 cm) fell on March 13, 1993, during the 1993 Storm of the Century, which established the highest daily snowfall and one-storm fall. March 1993 subsequently became the snowiest month on record, with a total of 13.0 inches (33.0 cm), also setting the record for highest season total. Average snowfall over the winter season, based on the 1981–2010 period, is 1.4 in (3.6 cm), but, for the same period, median monthly snowfall for each month was zero.
The spring and fall months are pleasant but variable as cold fronts frequently bring strong to severe thunderstorms and occasional tornadoes to the region. The fall season (primarily October) features less rainfall and fewer storms, as well as lower humidity than the spring, but November and early December represent a secondary severe weather season. Birmingham is in the heart of a Tornado Alley known as the Dixie Alley due to the high frequency of tornadoes in Central Alabama. The greater Birmingham area has been hit by two F5 tornadoes; one in Birmingham’s northern suburbs in 1977, and second in the western suburbs in 1998. The area was hit by an EF4 tornado which was part of the 2011 Super Outbreak and an EF3 Tornado in 2021. In late summer and fall months, Birmingham experiences occasional tropical storms and hurricanes due to its proximity to the Central Gulf Coast.
The record high temperature is 107 °F (42 °C), set on July 29, 1930, and the record low is −10 °F (−23 °C), set on February 13, 1899. The highest minimum temperature is 81 °F (27 °C), most recently on July 8, 2016, and the lowest maximum temperature 13 °F (−11 °C) on December 12, 1962. The driest month on record is October 1924, which reported no precipitation, and the wettest is July 1916, with a total of 20.12 inches (511 mm). The driest year on record is 2007, with a total of 28.86 inches (733 mm) and the wettest is 1929, with a total of 81.82 inches (2,078 mm).