USDA Hardiness Zone 8a
Frost Dates for 35645 — Killen, Alabama
NOAA 1991–2020 normals from Lexington, AL (760 ft), 9 miles northeast.
Updated
In Killen, the last spring frost (32°F) is around March 29 in half of years and has passed by April 15 in nine years out of ten. The first fall frost comes around November 4, as early as October 21 one year in ten, leaving a typical freeze-free season of 219 days (NOAA, Lexington, AL).
- Last spring frost
- March 29
- First fall frost
- November 4
- Growing season
- 219 days
- Hardiness zone
- 8a
50% probability
50% probability
freeze-free, 50%
10 to 15°F (-12.2 to -9.4°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 29%
- Snow per year
- 0.6"
median, 1991–2020
median, 1991–2020
6 of 21 observed
NOAA normal
Frost risk by date in Killen
Half of springs at Lexington, AL see their last 32°F night by March 29; only one in ten is past it by March 10, and one in ten still has one after April 15. Planting tender crops after April 5 leaves a 30% risk of a frost on them, after April 9 20%, and after April 15 10%. The 17 days between the even-odds date and the one-in-ten date is narrower than at 64% of the 115 Alabama stations behind this site's ZIP pages.
In fall the first 32°F night comes by November 4 in half of years, as early as October 21 one year in ten, and holds off past November 23 one year in ten. A hard freeze of 28°F follows 12 days later, around November 16; in spring the one-in-ten date for 28°F is April 3, 12 days before the 32°F one. The freeze-free season lasts 219 days in a typical year, shorter than at 75% of the 115 Alabama stations; it reaches 245 days one year in ten and falls short of 197 one year in ten. On average 70 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 10, and return around October 26. Nights of 24°F, cold enough to damage hardier plants, come in 100% of winters and 16°F in 89%.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Mar 25 | Mar 31 | Apr 4 | Apr 7 | Apr 10 | Apr 13 | Apr 16 | Apr 21 | Apr 26 |
| 32°F | Mar 10 | Mar 17 | Mar 21 | Mar 25 | Mar 29 | Apr 1 | Apr 5 | Apr 9 | Apr 15 |
| 28°F | Feb 24 | Mar 2 | Mar 7 | Mar 12 | Mar 15 | Mar 19 | Mar 24 | Mar 30 | Apr 3 |
| 24°F | Feb 9 | Feb 16 | Feb 22 | Feb 26 | Mar 2 | Mar 6 | Mar 10 | Mar 16 | Mar 23 |
| 20°F99% of yrs | Jan 22 | Jan 31 | Feb 6 | Feb 12 | Feb 17 | Feb 23 | Feb 28 | Mar 5 | Mar 12 |
| 16°F89% of yrs | Jan 5 | Jan 15 | Jan 22 | Jan 28 | Jan 31 | Feb 5 | Feb 11 | Feb 19 | Feb 28 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 14 | Oct 17 | Oct 20 | Oct 23 | Oct 26 | Oct 28 | Oct 31 | Nov 2 | Nov 7 |
| 32°F | Oct 21 | Oct 25 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 15 | Nov 23 |
| 28°F | Nov 1 | Nov 5 | Nov 9 | Nov 12 | Nov 16 | Nov 20 | Nov 25 | Dec 1 | Dec 7 |
| 24°F | Nov 10 | Nov 17 | Nov 23 | Nov 28 | Dec 1 | Dec 5 | Dec 10 | Dec 20 | Dec 30 |
| 20°F99% of yrs | Nov 23 | Dec 1 | Dec 7 | Dec 13 | Dec 21 | Dec 26 | Jan 1 | Jan 5 | Jan 15 |
| 16°F89% of yrs | Dec 5 | Dec 14 | Dec 25 | Jan 1 | Jan 3 | Jan 8 | Jan 13 | Jan 18 | Jan 31 |
Freeze probabilities 1991–2020 at Lexington, 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 35645 →Compare Killen with another place →
Weather by month in Killen
July is the warmest month at Lexington, AL, averaging 90°F by day and 69°F at night; January is the coldest at 51°F and 31°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 42% of years.
Warmth for growing adds up to 5,031 growing degree days a year (base 50°F), fewer than at 77% of the 115 Alabama stations. 39% of them (1,981) have built up by the end of June, and July adds the most, 913. Precipitation totals 58.6 inches a year, most in January (6.0") and least in October (3.6"); May to September bring 38% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 51 | 31 | 6.0 | 100% | 19 | 39 |
| Feb | 55 | 34 | 5.5 | 100% | 15 | 58 |
| Mar | 64 | 41 | 5.5 | 94% | 8 | 167 |
| Apr | 73 | 49 | 5.3 | 42% | 1 | 343 |
| May | 80 | 58 | 5.5 | 0% | 0 | 580 |
| Jun | 87 | 66 | 4.6 | 0% | 0 | 795 |
| Jul | 90 | 69 | 3.9 | 0% | 0 | 913 |
| Aug | 90 | 68 | 4.0 | 0% | 0 | 896 |
| Sep | 84 | 62 | 4.5 | 0% | 0 | 690 |
| Oct | 74 | 50 | 3.6 | 35% | 2 | 372 |
| Nov | 62 | 40 | 4.2 | 94% | 9 | 121 |
| Dec | 53 | 35 | 6.0 | 100% | 16 | 58 |
Monthly normals 1991–2020 at Lexington, AL (760 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, Muscle Shoals 2 N, AL, 12 miles southwest of Killen and 230 feet lower, has a last frost 2 days earlier (March 27), a first frost 1 day earlier (November 3), a season 1 day longer.
When it snows in Killen, Alabama
Measurable snow is rare here: only 6 of 21 winters from 1991 to 2020 recorded 0.1 inch or more at Russellville #2, AL, 30.1 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 35645
| When | What to do |
|---|---|
| January 18 – February 1 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 1 – February 15 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 1 – March 15 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| March 29 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 12 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 21 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| November 4 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 35645 is 9 miles from Lexington, AL, which stands at 760 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 4 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 35645 in zone 8a, the band where the coldest night of the year averaged 10 to 15°F (-12.2 to -9.4°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.