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USDA Hardiness Zone 8b

Frost Dates for 35211 — Birmingham, Alabama

NOAA 1991–2020 normals from Birmingham Airport, AL (615 ft), 9 miles northeast.

Updated

In Birmingham, the last spring frost (32°F) is around March 21 in half of years and has passed by April 8 in nine years out of ten. The first fall frost comes around November 11, as early as October 30 one year in ten, leaving a typical freeze-free season of 236 days (NOAA, Birmingham Airport, AL).

Last spring frost
March 21

50% probability

First fall frost
November 11

50% probability

Growing season
236 days

freeze-free, 50%

Hardiness zone
8b

15 to 20°F (-9.4 to -6.7°C) coldest night

First snow
Rare

median, 1991–2020

Last snow
Rare

median, 1991–2020

Winters with snow
14%

3 of 22 observed

Snow per year
1.2"

NOAA normal

Frost risk by date in Birmingham

Half of springs at Birmingham Airport, AL see their last 32°F night by March 21; only one in ten is past it by February 28, and one in ten still has one after April 8. Planting tender crops after March 30 leaves a 30% risk of a frost on them, after April 2 20%, and after April 8 10%. The 18 days between the even-odds date and the one-in-ten date is narrower than at 46% of the 115 Alabama stations behind this site's ZIP pages.

In fall the first 32°F night comes by November 11 in half of years, as early as October 30 one year in ten, and holds off past December 1 one year in ten. A hard freeze of 28°F follows 13 days later, around November 24; in spring the one-in-ten date for 28°F is March 26, 13 days before the 32°F one. The freeze-free season lasts 236 days in a typical year, longer than at 58% of the 115 Alabama stations; it reaches 262 days one year in ten and falls short of 211 one year in ten. On average 47 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 13 days longer, to about April 3, and return around November 2. Nights of 24°F, cold enough to damage hardier plants, come in 99% of winters and 16°F in 65%.

Spring: the chance of another night this cold after the date
Low90%80%70%60%50%40%30%20%10%
36°FMar 16Mar 23Mar 28Mar 31Apr 3Apr 6Apr 10Apr 14Apr 20
32°FFeb 28Mar 6Mar 13Mar 17Mar 21Mar 26Mar 30Apr 2Apr 8
28°FFeb 14Feb 21Feb 27Mar 2Mar 7Mar 11Mar 15Mar 20Mar 26
24°F99% of yrsJan 26Feb 2Feb 9Feb 15Feb 20Feb 26Mar 2Mar 8Mar 14
20°F92% of yrsJan 5Jan 17Jan 26Jan 31Feb 4Feb 11Feb 19Feb 27Mar 5
16°F65% of yrsJan 2Jan 8Jan 15Jan 20Jan 26Jan 31Feb 3Feb 13Feb 28
Fall: the chance the first night this cold has come by the date
Low10%20%30%40%50%60%70%80%90%
36°FOct 21Oct 26Oct 29Oct 31Nov 2Nov 4Nov 7Nov 10Nov 17
32°FOct 30Nov 3Nov 6Nov 8Nov 11Nov 15Nov 19Nov 23Dec 1
28°FNov 6Nov 11Nov 15Nov 20Nov 24Nov 28Dec 2Dec 6Dec 15
24°F99% of yrsNov 16Nov 23Nov 30Dec 4Dec 9Dec 16Dec 24Jan 1Jan 9
20°F92% of yrsDec 1Dec 9Dec 20Dec 26Jan 1Jan 4Jan 9Jan 16Jan 31
16°F65% of yrsDec 17Dec 29Jan 1Jan 6Jan 10Jan 16Jan 21Jan 28Feb 7

Freeze probabilities 1991–2020 at Birmingham Airport, AL, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.

Frost risk on any date in 35211 →Compare Birmingham with another place →

Weather by month in Birmingham

July is the warmest month at Birmingham Airport, AL, averaging 91°F by day and 72°F at night; January is the coldest at 55°F and 35°F. A freezing night is all but certain in every month from December to February (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, March still brings one in 85% of years and April still brings one in 26% of years.

Warmth for growing adds up to 5,764 growing degree days a year (base 50°F), more than at 61% of the 115 Alabama stations. 40% of them (2,323) have built up by the end of June, and July adds the most, 978. Precipitation totals 56.7 inches a year, most in March (5.7") and least in October (3.3"); May to September bring 41% of it.

Monthly normals 1991–2020 at Birmingham Airport, AL
MonthHigh °FLow °FPrecip. in32°F nightNights ≤ 32°FGDD 50°F
Jan55355.0100%1565
Feb59385.097%1094
Mar67455.785%4236
Apr75525.126%1412
May82614.90%0667
Jun88694.80%0849
Jul91725.40%0978
Aug91714.40%0959
Sep86654.00%0768
Oct76543.313%<1468
Nov65434.288%5180
Dec57384.998%1288

Monthly normals 1991–2020 at Birmingham Airport, AL (615 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.

Compared with the next station

The nearest other station, Bessemer 3 WSW, AL, 10 miles southwest of Birmingham and 170 feet lower, has a last frost 2 days later (March 23), a first frost 1 day earlier (November 10), a season 5 days shorter.

Frost dates for 35020 (Bessemer) →

When it snows in Birmingham, Alabama

Measurable snow is rare here: only 3 of 22 winters from 1991 to 2020 recorded 0.1 inch or more at Bessemer 3 WSW, AL, 10.4 miles away, so there is no typical first-snow date to plan around.

Planting calendar for 35211

What to do and when, from the 50% frost dates for Birmingham, Alabama
WhenWhat to do
January 10 – January 24Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
January 24 – February 7Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
February 21 – March 7Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
March 21 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by August 19Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by October 28Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
November 11 onwardPlant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter.

The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.

Where these figures come from

ZIP 35211 is 9 miles from Birmingham Airport, AL, which stands at 615 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 26 other ZIP codes share the station; its figures are presented in full for 35242 (Birmingham). The 2023 USDA Plant Hardiness Zone Map lists ZIP 35211 in zone 8b, the band where the coldest night of the year averaged 15 to 20°F (-9.4 to -6.7°C) over 1991–2020; a zone describes winter lows, not frost dates.

Frost dates across Alabama →

Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.

Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.

ZIP codes measured at the same station

Other zone 8b places in Alabama