USDA Hardiness Zone 7a
Frost Dates for 37659 — Jonesborough, Tennessee
NOAA 1991–2020 normals from Erwin 1 W, TN (1,720 ft), 11 miles south.
Updated
In Jonesborough, the last spring frost (32°F) is around April 21 in half of years and has passed by May 11 in nine years out of ten. The first fall frost comes around October 23, as early as October 11 one year in ten, leaving a typical freeze-free season of 183 days (NOAA, Erwin 1 W, TN).
- Last spring frost
- April 21
- First fall frost
- October 23
- Growing season
- 183 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
- December 26
- Last snow
- March 4
- Winters with snow
- 83%
- Snow per year
- 9.3"
median, 1991–2020
median, 1991–2020
25 of 30 observed
NOAA normal
Frost risk by date in Jonesborough
Half of springs at Erwin 1 W, 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 11. Planting tender crops after April 30 leaves a 30% risk of a frost on them, after May 5 20%, and after May 11 10%. The 20 days between the even-odds date and the one-in-ten date is wider than at 95% of the 144 Tennessee stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 23 in half of years, as early as October 11 one year in ten, and holds off past November 4 one year in ten. A hard freeze of 28°F follows 9 days later, around November 1; in spring the one-in-ten date for 28°F is April 30, 11 days before the 32°F one. The freeze-free season lasts 183 days in a typical year, shorter than at 92% of the 144 Tennessee stations; it reaches 203 days one year in ten and falls short of 160 one year in ten. On average 98 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 May 3, and return around October 14. Severe cold of 16°F or below comes every winter, usually between December 9 and February 26.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 18 | Apr 23 | Apr 27 | Apr 30 | May 3 | May 7 | May 10 | May 13 | May 20 |
| 32°F | Apr 4 | Apr 10 | Apr 15 | Apr 18 | Apr 21 | Apr 25 | Apr 30 | May 5 | May 11 |
| 28°F | Mar 20 | Mar 28 | Mar 31 | Apr 4 | Apr 7 | Apr 11 | Apr 16 | Apr 21 | Apr 30 |
| 24°F | Mar 6 | Mar 14 | Mar 18 | Mar 22 | Mar 26 | Mar 30 | Apr 2 | Apr 6 | Apr 12 |
| 20°F | Feb 17 | Feb 26 | Mar 2 | Mar 7 | Mar 12 | Mar 16 | Mar 21 | Mar 26 | Mar 31 |
| 16°F | Jan 29 | Feb 5 | Feb 12 | Feb 19 | Feb 26 | Mar 2 | Mar 7 | Mar 13 | Mar 21 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 3 | Oct 7 | Oct 10 | Oct 12 | Oct 14 | Oct 16 | Oct 20 | Oct 23 | Oct 27 |
| 32°F | Oct 11 | Oct 14 | Oct 17 | Oct 21 | Oct 23 | Oct 25 | Oct 28 | Nov 1 | Nov 4 |
| 28°F | Oct 18 | Oct 23 | Oct 26 | Oct 29 | Nov 1 | Nov 2 | Nov 5 | Nov 8 | Nov 13 |
| 24°F | Oct 28 | Nov 1 | Nov 4 | Nov 6 | Nov 9 | Nov 13 | Nov 17 | Nov 21 | Nov 27 |
| 20°F | Nov 7 | Nov 12 | Nov 16 | Nov 21 | Nov 25 | Nov 29 | Dec 1 | Dec 7 | Dec 14 |
| 16°F | Nov 18 | Nov 25 | Dec 1 | Dec 4 | Dec 9 | Dec 15 | Dec 23 | Dec 30 | Jan 5 |
Freeze probabilities 1991–2020 at Erwin 1 W, 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 37659 →Compare Jonesborough with another place →
Frost risk through the year in Jonesborough
In Jonesborough, the spring curve drops under 10% on May 11 and the fall curve passes 10% on October 11, 153 days later; that gap is shorter than at 93% of the 144 Tennessee stations with frost dates. The spring risk falls from 90% to 10% over 37 days (April 4 to May 11) and the fall risk climbs from 10% to 90% over 24 days (October 11 to November 4): the last frost moves more from year to year than the first. At Bristol Tri City Airport, TN, 13 miles northeast, the same gap runs from May 5 to October 11, 6 days longer.
| Planted on | Another 32°F night | 28°F night |
|---|---|---|
| Apr 7 | 85% | 50% |
| Apr 14 | 72% | 34% |
| Apr 2150% date | 50% | 20% |
| Apr 28 | 34% | 12% |
| May 5 | 20% | under 10% |
| May 12 | under 10% | under 10% |
Weather by month in Jonesborough
July is the warmest month at Erwin 1 W, TN, averaging 85°F by day and 62°F at night; January is the coldest at 47°F and 25°F. A freezing night is all but certain in every month from November 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 29% of years.
Warmth for growing adds up to 3,607 growing degree days a year (base 50°F), fewer than at 94% of the 144 Tennessee stations. 36% of them (1,307) have built up by the end of June, and July adds the most, 738. Precipitation totals 47.0 inches a year, most in July (5.5") and least in October (2.5"); May to September bring 50% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 47 | 25 | 3.5 | 100% | 22 | 12 |
| Feb | 51 | 27 | 3.3 | 100% | 19 | 16 |
| Mar | 59 | 33 | 3.8 | 100% | 14 | 66 |
| Apr | 68 | 41 | 4.0 | 92% | 4 | 190 |
| May | 76 | 50 | 4.8 | 29% | 1 | 409 |
| Jun | 83 | 58 | 5.1 | 0% | 0 | 613 |
| Jul | 85 | 62 | 5.5 | 0% | 0 | 738 |
| Aug | 85 | 61 | 4.8 | 0% | 0 | 713 |
| Sep | 80 | 55 | 3.3 | 0% | 0 | 529 |
| Oct | 70 | 43 | 2.5 | 79% | 3 | 240 |
| Nov | 59 | 33 | 2.8 | 100% | 15 | 59 |
| Dec | 50 | 28 | 3.6 | 100% | 20 | 21 |
Monthly normals 1991–2020 at Erwin 1 W, TN (1,720 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, Bristol Tri City Airport, TN, 13 miles northeast of Jonesborough and 220 feet lower, has a last frost 5 days earlier (April 16), a first frost 1 day later (October 24), a season 7 days longer.
When it snows in Jonesborough, Tennessee
The first measurable snow (0.1 inch or more) in Jonesborough usually arrives around December 26, and the last of the season around March 4. Those are the middle dates across the winters of 1991–2020 at Erwin 1 W, TN, 11.2 miles away: half of years saw snow earlier, half later. Snow fell in 83% of those winters. The last 32°F night of spring typically comes 48 days after the last snow.
Planting calendar for 37659
| 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 31 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 9 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 23 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 37659 is 11 miles from Erwin 1 W, TN, which stands at 1,720 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 37659 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.