USDA Hardiness Zone 8a
Frost Dates for 35673 — Trinity, Alabama
NOAA 1991–2020 normals from Decatur 4SE, AL (550 ft), 11 miles east.
Updated
In Trinity, the last spring frost (32°F) is around March 26 in half of years and has passed by April 9 in nine years out of ten. The first fall frost comes around November 7, as early as October 26 one year in ten, leaving a typical freeze-free season of 228 days (NOAA, Decatur 4SE, AL).
- Last spring frost
- March 26
- First fall frost
- November 7
- Growing season
- 228 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
- 43%
- Snow per year
- 1.3"
median, 1991–2020
median, 1991–2020
10 of 23 observed
NOAA normal
Frost risk by date in Trinity
Half of springs at Decatur 4SE, AL see their last 32°F night by March 26; only one in ten is past it by March 5, and one in ten still has one after April 9. Planting tender crops after April 1 leaves a 30% risk of a frost on them, after April 5 20%, and after April 9 10%. The 14 days between the even-odds date and the one-in-ten date is the narrowest of the 115 Alabama stations behind this site's ZIP pages.
In fall the first 32°F night comes by November 7 in half of years, as early as October 26 one year in ten, and holds off past November 26 one year in ten. A hard freeze of 28°F follows 12 days later, around November 19; in spring the one-in-ten date for 28°F is March 30, 10 days before the 32°F one. The freeze-free season lasts 228 days in a typical year, shorter than at 58% of the 115 Alabama stations; it reaches 252 days one year in ten and falls short of 205 one year in ten. On average 52 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 10 days longer, to about April 5, and return around October 29. Nights of 24°F, cold enough to damage hardier plants, come in 100% of winters and 16°F in 82%.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Mar 21 | Mar 27 | Mar 31 | Apr 3 | Apr 5 | Apr 8 | Apr 11 | Apr 15 | Apr 22 |
| 32°F | Mar 5 | Mar 14 | Mar 18 | Mar 22 | Mar 26 | Mar 29 | Apr 1 | Apr 5 | Apr 9 |
| 28°F | Feb 21 | Feb 28 | Mar 3 | Mar 7 | Mar 12 | Mar 16 | Mar 19 | Mar 23 | Mar 30 |
| 24°F | Feb 4 | Feb 12 | Feb 18 | Feb 22 | Feb 26 | Mar 1 | Mar 6 | Mar 12 | Mar 18 |
| 20°F98% of yrs | Jan 15 | Jan 25 | Jan 31 | Feb 4 | Feb 10 | Feb 15 | Feb 22 | Feb 28 | Mar 6 |
| 16°F82% of yrs | Jan 1 | Jan 10 | Jan 17 | Jan 23 | Jan 28 | Jan 31 | Feb 4 | Feb 12 | Feb 24 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 16 | Oct 21 | Oct 24 | Oct 26 | Oct 29 | Oct 31 | Nov 3 | Nov 6 | Nov 11 |
| 32°F | Oct 26 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 13 | Nov 18 | Nov 26 |
| 28°F | Nov 4 | Nov 7 | Nov 11 | Nov 15 | Nov 19 | Nov 23 | Nov 28 | Dec 3 | Dec 10 |
| 24°F | Nov 12 | Nov 18 | Nov 25 | Nov 30 | Dec 3 | Dec 7 | Dec 13 | Dec 22 | Jan 1 |
| 20°F98% of yrs | Nov 26 | Dec 2 | Dec 9 | Dec 16 | Dec 24 | Dec 30 | Jan 2 | Jan 9 | Jan 18 |
| 16°F82% of yrs | Dec 9 | Dec 19 | Dec 27 | Jan 1 | Jan 4 | Jan 8 | Jan 14 | Jan 20 | Jan 31 |
Freeze probabilities 1991–2020 at Decatur 4SE, 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 35673 →Compare Trinity with another place →
Weather by month in Trinity
July is the warmest month at Decatur 4SE, AL, averaging 89°F by day and 69°F at night; January is the coldest at 52°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 31% of years.
Warmth for growing adds up to 5,071 growing degree days a year (base 50°F), fewer than at 75% of the 115 Alabama stations. 40% of them (2,009) have built up by the end of June, and July adds the most, 908.
| Month | High °F | Low °F | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|
| Jan | 52 | 31 | 100% | 17 | 43 |
| Feb | 57 | 34 | 100% | 12 | 59 |
| Mar | 65 | 41 | 94% | 4 | 172 |
| Apr | 74 | 49 | 31% | <1 | 355 |
| May | 80 | 58 | 0% | 0 | 592 |
| Jun | 87 | 66 | 0% | 0 | 787 |
| Jul | 89 | 69 | 0% | 0 | 908 |
| Aug | 89 | 68 | 0% | 0 | 888 |
| Sep | 84 | 62 | 0% | 0 | 697 |
| Oct | 74 | 50 | 23% | <1 | 385 |
| Nov | 63 | 40 | 93% | 6 | 128 |
| Dec | 55 | 34 | 99% | 14 | 56 |
Monthly normals 1991–2020 at Decatur 4SE, AL (550 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, Moulton 2, AL, 12 miles southwest of Trinity, has a last frost 7 days later (April 2), a first frost 7 days earlier (October 31), a season 19 days shorter.
When it snows in Trinity, Alabama
Measurable snow is rare here: only 10 of 23 winters from 1991 to 2020 recorded 0.1 inch or more at Athens, AL, 16.4 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 35673
| When | What to do |
|---|---|
| January 15 – January 29 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| January 29 – February 12 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| February 26 – March 12 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| March 26 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 15 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 24 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| November 7 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 35673 is 11 miles from Decatur 4SE, AL, which stands at 550 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station; its figures are presented in full for 35601 (Decatur). The 2023 USDA Plant Hardiness Zone Map lists ZIP 35673 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.