USDA Hardiness Zone 7b
Frost Dates for 35978 — Henagar, Alabama
NOAA 1991–2020 normals from Valley Head 1 SSW, AL (1,020 ft), 8 miles southeast.
Updated
In Henagar, the last spring frost (32°F) is around April 7 in half of years and has passed by April 25 in nine years out of ten. The first fall frost comes around October 30, as early as October 18 one year in ten, leaving a typical freeze-free season of 204 days (NOAA, Valley Head 1 SSW, AL).
- Last spring frost
- April 7
- First fall frost
- October 30
- Growing season
- 204 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
- January 18
- Last snow
- February 13
- Winters with snow
- 91%
- Snow per year
- 5"
median, 1991–2020
median, 1991–2020
20 of 22 observed
NOAA normal
Frost risk by date in Henagar
Half of springs at Valley Head 1 SSW, AL see their last 32°F night by April 7; only one in ten is past it by March 20, and one in ten still has one after April 25. Planting tender crops after April 14 leaves a 30% risk of a frost on them, after April 19 20%, and after April 25 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 October 30 in half of years, as early as October 18 one year in ten, and holds off past November 12 one year in ten. A hard freeze of 28°F follows 9 days later, around November 8; in spring the one-in-ten date for 28°F is April 14, 11 days before the 32°F one. The freeze-free season lasts 204 days in a typical year, shorter than at 96% of the 115 Alabama stations; it reaches 226 days one year in ten and falls short of 182 one year in ten. On average 78 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 14 days longer, to about April 21, and return around October 21. Severe cold of 16°F or below comes in 95% of winters, usually between December 30 and February 9.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 3 | Apr 9 | Apr 13 | Apr 16 | Apr 21 | Apr 24 | Apr 28 | May 1 | May 6 |
| 32°F | Mar 20 | Mar 27 | Mar 31 | Apr 4 | Apr 7 | Apr 11 | Apr 14 | Apr 19 | Apr 25 |
| 28°F | Mar 5 | Mar 13 | Mar 17 | Mar 22 | Mar 27 | Mar 31 | Apr 3 | Apr 8 | Apr 14 |
| 24°F | Feb 16 | Feb 24 | Feb 28 | Mar 5 | Mar 10 | Mar 15 | Mar 19 | Mar 25 | Mar 31 |
| 20°F | Jan 28 | Feb 5 | Feb 14 | Feb 21 | Feb 25 | Mar 1 | Mar 6 | Mar 12 | Mar 19 |
| 16°F95% of yrs | Jan 11 | Jan 22 | Jan 29 | Feb 2 | Feb 9 | Feb 16 | Feb 22 | Feb 28 | Mar 8 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 10 | Oct 13 | Oct 17 | Oct 19 | Oct 21 | Oct 24 | Oct 26 | Oct 29 | Nov 3 |
| 32°F | Oct 18 | Oct 21 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 12 |
| 28°F | Oct 25 | Oct 31 | Nov 2 | Nov 5 | Nov 8 | Nov 11 | Nov 15 | Nov 20 | Nov 28 |
| 24°F | Nov 5 | Nov 8 | Nov 13 | Nov 17 | Nov 21 | Nov 25 | Dec 1 | Dec 5 | Dec 16 |
| 20°F | Nov 13 | Nov 22 | Nov 29 | Dec 2 | Dec 7 | Dec 14 | Dec 24 | Dec 31 | Jan 8 |
| 16°F95% of yrs | Dec 1 | Dec 7 | Dec 15 | Dec 24 | Dec 30 | Jan 3 | Jan 7 | Jan 15 | Jan 27 |
Freeze probabilities 1991–2020 at Valley Head 1 SSW, 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 35978 →Compare Henagar with another place →
Weather by month in Henagar
July is the warmest month at Valley Head 1 SSW, AL, averaging 87°F by day and 66°F at night; January is the coldest at 50°F and 30°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 68% of years.
Warmth for growing adds up to 4,344 growing degree days a year (base 50°F), the fewest of the 115 Alabama stations. 38% of them (1,652) have built up by the end of June, and July adds the most, 825. Precipitation totals 56.4 inches a year, most in December (5.5") and least in August (3.5"); May to September bring 40% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 50 | 30 | 4.7 | 100% | 20 | 32 |
| Feb | 55 | 32 | 5.4 | 100% | 16 | 44 |
| Mar | 62 | 39 | 5.2 | 98% | 9 | 120 |
| Apr | 71 | 46 | 5.1 | 68% | 2 | 267 |
| May | 78 | 54 | 4.4 | 3% | 0 | 491 |
| Jun | 84 | 63 | 4.8 | 0% | 0 | 699 |
| Jul | 87 | 66 | 5.2 | 0% | 0 | 825 |
| Aug | 87 | 66 | 3.5 | 0% | 0 | 815 |
| Sep | 81 | 59 | 4.5 | 0% | 0 | 609 |
| Oct | 72 | 48 | 3.6 | 57% | 2 | 313 |
| Nov | 61 | 37 | 4.5 | 98% | 12 | 86 |
| Dec | 53 | 33 | 5.5 | 100% | 17 | 45 |
Monthly normals 1991–2020 at Valley Head 1 SSW, AL (1,020 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, Valley Head, AL, 9 miles southeast of Henagar, has a last frost 1 day later (April 8), a first frost 1 day earlier (October 29), a season 2 days shorter.
When it snows in Henagar, Alabama
The first measurable snow (0.1 inch or more) in Henagar usually arrives around January 18, and the last of the season around February 13. Those are the middle dates across the winters of 1991–2020 at Valley Head, AL, 8.6 miles away: half of years saw snow earlier, half later. Snow fell in 91% of those winters. The last 32°F night of spring typically comes 53 days after the last snow.
Planting calendar for 35978
| When | What to do |
|---|---|
| January 27 – February 10 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 10 – February 24 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 10 – March 24 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 7 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 7 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 16 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 30 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 35978 is 8 miles from Valley Head 1 SSW, AL, which stands at 1,020 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 35978 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.