Frost Dates
Frost Dates · Alabama

Frost dates for Birmingham, Alabama

Alabama · first & last freeze, from NOAA 1991–2020 climate normals

Typical last spring freeze (32°F)
March 21
median date, 1991–2020
Typical first fall freeze (32°F)
November 11
median date, 1991–2020
Typical frost-free season
235 days
between the median dates

In a typical year, the last spring freeze around Birmingham comes near March 21 and the first fall freeze near November 11. One year in ten, a freeze still arrives after April 8 in spring — and one year in ten, the first fall freeze has already landed by October 30. NCEI's own growing-season statistic (days between freezes, percentiled per year) puts the median at 236 days.

JFMAMJJASONDMarch 21November 11
The year at a glance: blue bands span the 9-in-10 to 1-in-10 range where the last spring / first fall 32°F freeze lands; the green band is the typical frost-free window between the median dates. Measured at Birmingham Ap, AL (USW00013876), 4.0 mi from the city's census reference point, elev. 615 ft. NOAA/NCEI 1991–2020 normals.

Freeze-date probabilities, three thresholds

ThresholdLast spring — 9 in 10 years past byLast spring — typical (median)Last spring — 1 in 10 years later thanFirst fall — 1 in 10 years byFirst fall — typical (median)First fall — 9 in 10 years by
36°F — near-freezing (frost can occur)March 16April 3April 20October 21November 2November 17
32°F — freezingFebruary 28March 21April 8October 30November 11December 1
28°F — hard freezeFebruary 14March 7March 26November 6November 24December 15

Measured at Birmingham Ap, AL (USW00013876), 4.0 mi from the city's census reference point, elev. 615 ft. NOAA/NCEI 1991–2020 normals. Read each date column as odds over the 30-year record — e.g. "9 in 10 years past by" means only one spring in ten saw a later freeze than that date.

Frost-free windows (computed)

Window (32°F ends)OpensClosesLength
Cautious (1-in-10 freeze risk at each end)April 8October 30205 days
Typical (median freeze dates)March 21November 11235 days
Gambler's (9-in-10 freeze risk at each end)February 28December 1276 days

Pure arithmetic on the freeze-date percentiles above — the "cautious" window opens on the date only 1 year in 10 still sees a later spring freeze, and closes on the date by which only 1 year in 10 has already frozen.

About this city's numbers

More Alabama cities

Huntsville · Mobile · Montgomery · Tuscaloosa · Hoover · all of Alabama →