USDA Hardiness Zone 7b
Frost Dates for 35570 — Hamilton, Alabama
NOAA 1991–2020 normals from Hamilton 3 S, AL (435 ft), 4 miles south.
Updated
In Hamilton, the last spring frost (32°F) is around April 11 in half of years and has passed by April 27 in nine years out of ten. The first fall frost comes around October 27, as early as October 15 one year in ten, leaving a typical freeze-free season of 198 days (NOAA, Hamilton 3 S, AL).
- Last spring frost
- April 11
- First fall frost
- October 27
- Growing season
- 198 days
- Hardiness zone
- 7b
50% probability
50% probability
freeze-free, 50%
5 to 10°F (-15.0 to -12.2°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 25%
- Snow per year
- 0.6"
median, 1991–2020
median, 1991–2020
5 of 20 observed
NOAA normal
Frost risk by date in Hamilton
Half of springs at Hamilton 3 S, AL see their last 32°F night by April 11; only one in ten is past it by March 26, and one in ten still has one after April 27. Planting tender crops after April 18 leaves a 30% risk of a frost on them, after April 22 20%, and after April 27 10%. The 16 days between the even-odds date and the one-in-ten date is narrower than at 80% of the 115 Alabama stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 27 in half of years, as early as October 15 one year in ten, and holds off past November 10 one year in ten. A hard freeze of 28°F follows 8 days later, around November 4; in spring the one-in-ten date for 28°F is April 16, 11 days before the 32°F one. The freeze-free season lasts 198 days in a typical year, the shortest of the 115 Alabama stations; it reaches 220 days one year in ten and falls short of 178 one year in ten. On average 96 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 12 days longer, to about April 23, and return around October 19. Severe cold of 16°F or below comes in 97% of winters, usually between December 23 and February 13.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 7 | Apr 12 | Apr 16 | Apr 20 | Apr 23 | Apr 26 | Apr 30 | May 2 | May 7 |
| 32°F | Mar 26 | Mar 31 | Apr 5 | Apr 8 | Apr 11 | Apr 14 | Apr 18 | Apr 22 | Apr 27 |
| 28°F | Mar 11 | Mar 18 | Mar 23 | Mar 27 | Mar 31 | Apr 3 | Apr 6 | Apr 10 | Apr 16 |
| 24°F | Feb 24 | Mar 1 | Mar 6 | Mar 11 | Mar 16 | Mar 20 | Mar 25 | Mar 30 | Apr 4 |
| 20°F | Feb 5 | Feb 14 | Feb 21 | Feb 26 | Mar 1 | Mar 5 | Mar 10 | Mar 15 | Mar 21 |
| 16°F97% of yrs | Jan 17 | Jan 28 | Feb 2 | Feb 7 | Feb 13 | Feb 20 | Feb 27 | Mar 4 | Mar 11 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 7 | Oct 11 | Oct 14 | Oct 17 | Oct 19 | Oct 22 | Oct 24 | Oct 27 | Oct 31 |
| 32°F | Oct 15 | Oct 19 | Oct 22 | Oct 25 | Oct 27 | Oct 30 | Nov 1 | Nov 3 | Nov 10 |
| 28°F | Oct 22 | Oct 28 | Oct 31 | Nov 1 | Nov 4 | Nov 7 | Nov 13 | Nov 18 | Nov 25 |
| 24°F | Nov 1 | Nov 4 | Nov 8 | Nov 13 | Nov 17 | Nov 21 | Nov 26 | Dec 1 | Dec 7 |
| 20°F | Nov 9 | Nov 17 | Nov 23 | Nov 28 | Dec 2 | Dec 7 | Dec 13 | Dec 24 | Jan 1 |
| 16°F97% of yrs | Nov 22 | Dec 1 | Dec 8 | Dec 15 | Dec 23 | Dec 30 | Jan 3 | Jan 11 | Jan 25 |
Freeze probabilities 1991–2020 at Hamilton 3 S, 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 35570 →Compare Hamilton with another place →
Weather by month in Hamilton
July is the warmest month at Hamilton 3 S, AL, averaging 92°F by day and 68°F at night; January is the coldest at 53°F and 28°F. A freezing night is all but certain in every month from November to March (a 90% chance or more). From May to September the chance of a 32°F night stays under 10% each month. In spring, April still brings one in 79% of years.
Warmth for growing adds up to 5,001 growing degree days a year (base 50°F), fewer than at 79% of the 115 Alabama stations. 39% of them (1,931) have built up by the end of June, and July adds the most, 924. Precipitation totals 61.7 inches a year, most in December (6.4") and least in October (3.8"); May to September bring 39% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 53 | 28 | 5.5 | 100% | 22 | 38 |
| Feb | 58 | 31 | 6.0 | 100% | 18 | 53 |
| Mar | 67 | 38 | 5.3 | 99% | 13 | 158 |
| Apr | 75 | 45 | 6.1 | 79% | 4 | 320 |
| May | 82 | 55 | 5.8 | 4% | <1 | 574 |
| Jun | 89 | 64 | 4.9 | 0% | 0 | 789 |
| Jul | 92 | 68 | 5.1 | 0% | 0 | 924 |
| Aug | 91 | 67 | 4.3 | 0% | 0 | 902 |
| Sep | 87 | 60 | 3.9 | 0% | 0 | 699 |
| Oct | 76 | 47 | 3.8 | 66% | 4 | 374 |
| Nov | 64 | 36 | 4.6 | 99% | 15 | 118 |
| Dec | 55 | 31 | 6.4 | 100% | 20 | 53 |
Monthly normals 1991–2020 at Hamilton 3 S, AL (435 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, Winfield 2 SW, AL, 19 miles southeast of Hamilton, has a last frost 7 days earlier (April 4), a first frost 5 days later (November 1), a season 13 days longer.
When it snows in Hamilton, Alabama
Measurable snow is rare here: only 5 of 20 winters from 1991 to 2020 recorded 0.1 inch or more at Sulligent, AL, 17.1 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 35570
| When | What to do |
|---|---|
| January 31 – February 14 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 14 – February 28 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 14 – March 28 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 11 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 4 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 13 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 27 onward | Plant 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 35570 is 4 miles from Hamilton 3 S, AL, which stands at 435 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 35570 in zone 7b, the band where the coldest night of the year averaged 5 to 10°F (-15.0 to -12.2°C) over 1991–2020; a zone describes winter lows, not frost dates.
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.