USDA Hardiness Zone 7a
Frost Dates for 37887 — Wartburg, Tennessee
NOAA 1991–2020 normals from Lancing 6 NW, TN (1,520 ft), 10 miles northwest.
Updated
In Wartburg, the last spring frost (32°F) is around April 21 in half of years and has passed by May 12 in nine years out of ten. The first fall frost comes around October 17, as early as October 4 one year in ten, leaving a typical freeze-free season of 177 days (NOAA, Lancing 6 NW, TN).
- Last spring frost
- April 21
- First fall frost
- October 17
- Growing season
- 177 days
- Hardiness zone
- 7a
50% probability
50% probability
freeze-free, 50%
0 to 5°F (-17.8 to -15.0°C) coldest night
- First snow
- January 3
- Last snow
- February 19
- Winters with snow
- 100%
- Snow per year
- 4.9"
median, 1991–2020
median, 1991–2020
22 of 22 observed
NOAA normal
Frost risk by date in Wartburg
Half of springs at Lancing 6 NW, TN see their last 32°F night by April 21; only one in ten is past it by April 4, and one in ten still has one after May 12. Planting tender crops after April 30 leaves a 30% risk of a frost on them, after May 4 20%, and after May 12 10%. The 21 days between the even-odds date and the one-in-ten date is the widest of the 144 Tennessee stations behind this site's ZIP pages, so a fixed calendar date is a gamble here.
In fall the first 32°F night comes by October 17 in half of years, as early as October 4 one year in ten, and holds off past October 30 one year in ten. A hard freeze of 28°F follows 10 days later, around October 27; in spring the one-in-ten date for 28°F is April 27, 15 days before the 32°F one. The freeze-free season lasts 177 days in a typical year, shorter than at 97% of the 144 Tennessee stations; it reaches 201 days one year in ten and falls short of 152 one year in ten. On average 107 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 May 4, and return around October 8. Severe cold of 16°F or below comes every winter, usually between December 6 and February 26.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 17 | Apr 23 | Apr 27 | Apr 30 | May 4 | May 8 | May 12 | May 16 | May 22 |
| 32°F | Apr 4 | Apr 9 | Apr 14 | Apr 17 | Apr 21 | Apr 25 | Apr 30 | May 4 | May 12 |
| 28°F | Mar 20 | Mar 26 | Mar 31 | Apr 2 | Apr 5 | Apr 9 | Apr 13 | Apr 19 | Apr 27 |
| 24°F | Feb 28 | Mar 11 | Mar 17 | Mar 21 | Mar 25 | Mar 29 | Apr 1 | Apr 4 | Apr 12 |
| 20°F | Feb 16 | Feb 24 | Mar 1 | Mar 6 | Mar 12 | Mar 17 | Mar 21 | Mar 27 | Apr 1 |
| 16°F | Jan 31 | Feb 8 | Feb 14 | Feb 20 | Feb 26 | Mar 3 | Mar 7 | Mar 14 | Mar 21 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 27 | Oct 1 | Oct 4 | Oct 6 | Oct 8 | Oct 11 | Oct 14 | Oct 17 | Oct 20 |
| 32°F | Oct 4 | Oct 9 | Oct 13 | Oct 15 | Oct 17 | Oct 20 | Oct 23 | Oct 25 | Oct 30 |
| 28°F | Oct 14 | Oct 18 | Oct 22 | Oct 25 | Oct 27 | Oct 30 | Nov 1 | Nov 5 | Nov 11 |
| 24°F | Oct 24 | Oct 30 | Nov 2 | Nov 5 | Nov 7 | Nov 11 | Nov 15 | Nov 19 | Nov 28 |
| 20°F | Nov 5 | Nov 8 | Nov 13 | Nov 16 | Nov 20 | Nov 26 | Dec 1 | Dec 5 | Dec 15 |
| 16°F | Nov 14 | Nov 21 | Nov 27 | Dec 1 | Dec 6 | Dec 12 | Dec 20 | Dec 28 | Jan 4 |
Freeze probabilities 1991–2020 at Lancing 6 NW, TN, 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 37887 →Compare Wartburg with another place →
Weather by month in Wartburg
July is the warmest month at Lancing 6 NW, TN, averaging 86°F by day and 63°F at night; January is the coldest at 46°F and 26°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to September the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 28% of years.
Warmth for growing adds up to 3,723 growing degree days a year (base 50°F), fewer than at 90% of the 144 Tennessee stations. 37% of them (1,392) have built up by the end of June, and July adds the most, 753. Precipitation totals 56.4 inches a year, most in April (5.9") and least in October (3.3"); May to September bring 41% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 46 | 26 | 4.8 | 100% | 23 | 12 |
| Feb | 50 | 28 | 4.6 | 100% | 20 | 16 |
| Mar | 59 | 35 | 5.0 | 99% | 15 | 85 |
| Apr | 69 | 42 | 5.9 | 92% | 6 | 221 |
| May | 76 | 51 | 4.7 | 28% | 1 | 426 |
| Jun | 83 | 59 | 5.1 | 0% | 0 | 633 |
| Jul | 86 | 63 | 5.7 | 0% | 0 | 753 |
| Aug | 85 | 62 | 3.4 | 0% | 0 | 724 |
| Sep | 80 | 54 | 4.3 | 5% | <1 | 522 |
| Oct | 70 | 43 | 3.3 | 93% | 6 | 242 |
| Nov | 59 | 34 | 3.9 | 100% | 14 | 67 |
| Dec | 50 | 29 | 5.7 | 100% | 22 | 21 |
Monthly normals 1991–2020 at Lancing 6 NW, TN (1,520 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, Kingston, TN, 16 miles south of Wartburg and 706 feet lower, has a last frost 18 days earlier (April 3), a first frost 18 days later (November 4), a season 38 days longer.
When it snows in Wartburg, Tennessee
The first measurable snow (0.1 inch or more) in Wartburg usually arrives around January 3, and the last of the season around February 19. Those are the middle dates across the winters of 1991–2020 at Lancing 6 NW, TN, 9.8 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 61 days after the last snow.
Planting calendar for 37887
| When | What to do |
|---|---|
| February 10 – February 24 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 24 – March 10 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 24 – April 7 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 21 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 25 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 3 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 17 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 37887 is 10 miles from Lancing 6 NW, TN, which stands at 1,520 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 37887 in zone 7a, the band where the coldest night of the year averaged 0 to 5°F (-17.8 to -15.0°C) over 1991–2020; a zone describes winter lows, not frost dates.
Frost dates across Tennessee →
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.