USDA Hardiness Zone 7b
Frost Dates for 37840 — Oliver Springs, Tennessee
NOAA 1991–2020 normals from Oak Ridge Atdd, TN (905 ft), 7 miles southeast.
Updated
In Oliver Springs, the last spring frost (32°F) is around April 5 in half of years and has passed by April 19 in nine years out of ten. The first fall frost comes around November 1, as early as October 19 one year in ten, leaving a typical freeze-free season of 210 days (NOAA, Oak Ridge Atdd, TN).
- Last spring frost
- April 5
- First fall frost
- November 1
- Growing season
- 210 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 6
- Last snow
- February 12
- Winters with snow
- 83%
- Snow per year
- 4.4"
median, 1991–2020
median, 1991–2020
25 of 30 observed
NOAA normal
Frost risk by date in Oliver Springs
Half of springs at Oak Ridge Atdd, TN see their last 32°F night by April 5; only one in ten is past it by March 19, and one in ten still has one after April 19. Planting tender crops after April 11 leaves a 30% risk of a frost on them, after April 15 20%, and after April 19 10%. The 14 days between the even-odds date and the one-in-ten date is narrower than at 95% of the 144 Tennessee stations behind this site's ZIP pages.
In fall the first 32°F night comes by November 1 in half of years, as early as October 19 one year in ten, and holds off past November 13 one year in ten. A hard freeze of 28°F follows 10 days later, around November 11; in spring the one-in-ten date for 28°F is April 9, 10 days before the 32°F one. The freeze-free season lasts 210 days in a typical year, longer than at 69% of the 144 Tennessee stations; it reaches 231 days one year in ten and falls short of 191 one year in ten. On average 75 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 17, and return around October 23. Severe cold of 16°F or below comes in 95% of winters, usually between December 30 and February 4.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 3 | Apr 7 | Apr 11 | Apr 14 | Apr 17 | Apr 20 | Apr 23 | Apr 27 | May 2 |
| 32°F | Mar 19 | Mar 25 | Mar 29 | Apr 2 | Apr 5 | Apr 8 | Apr 11 | Apr 15 | Apr 19 |
| 28°F | Mar 2 | Mar 10 | Mar 15 | Mar 19 | Mar 23 | Mar 27 | Mar 31 | Apr 3 | Apr 9 |
| 24°F | Feb 12 | Feb 22 | Feb 27 | Mar 3 | Mar 8 | Mar 12 | Mar 17 | Mar 22 | Mar 28 |
| 20°F | Jan 26 | Feb 4 | Feb 10 | Feb 15 | Feb 21 | Feb 26 | Mar 2 | Mar 8 | Mar 16 |
| 16°F95% of yrs | Jan 7 | Jan 18 | Jan 24 | Jan 31 | Feb 4 | Feb 9 | Feb 15 | Feb 26 | Mar 4 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 10 | Oct 14 | Oct 18 | Oct 21 | Oct 23 | Oct 26 | Oct 28 | Oct 31 | Nov 4 |
| 32°F | Oct 19 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 3 | Nov 5 | Nov 8 | Nov 13 |
| 28°F | Oct 31 | Nov 3 | Nov 6 | Nov 8 | Nov 11 | Nov 14 | Nov 17 | Nov 22 | Nov 28 |
| 24°F | Nov 8 | Nov 13 | Nov 16 | Nov 20 | Nov 25 | Nov 29 | Dec 2 | Dec 8 | Dec 18 |
| 20°F | Nov 19 | Nov 26 | Dec 1 | Dec 5 | Dec 10 | Dec 17 | Dec 23 | Dec 29 | Jan 6 |
| 16°F95% of yrs | Dec 2 | Dec 10 | Dec 18 | Dec 24 | Dec 30 | Jan 2 | Jan 8 | Jan 13 | Jan 23 |
Freeze probabilities 1991–2020 at Oak Ridge Atdd, 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 37840 →Compare Oliver Springs with another place →
Weather by month in Oliver Springs
July is the warmest month at Oak Ridge Atdd, TN, averaging 87°F by day and 68°F at night; January is the coldest at 47°F and 29°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 64% of years.
Warmth for growing adds up to 4,405 growing degree days a year (base 50°F), fewer than at 57% of the 144 Tennessee stations. 38% of them (1,678) have built up by the end of June, and July adds the most, 854. Precipitation totals 59.7 inches a year, most in February (5.9") and least in October (3.3"); May to September bring 39% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 47 | 29 | 5.5 | 100% | 20 | 16 |
| Feb | 51 | 32 | 5.9 | 100% | 16 | 25 |
| Mar | 61 | 39 | 5.6 | 97% | 9 | 111 |
| Apr | 70 | 47 | 5.6 | 64% | 2 | 280 |
| May | 78 | 56 | 4.5 | 0% | 0 | 525 |
| Jun | 84 | 64 | 4.8 | 0% | 0 | 721 |
| Jul | 87 | 68 | 5.9 | 0% | 0 | 854 |
| Aug | 87 | 67 | 3.7 | 0% | 0 | 831 |
| Sep | 81 | 61 | 4.1 | 0% | 0 | 624 |
| Oct | 71 | 48 | 3.3 | 47% | 1 | 317 |
| Nov | 59 | 37 | 5.0 | 99% | 11 | 79 |
| Dec | 49 | 32 | 5.8 | 100% | 17 | 23 |
Monthly normals 1991–2020 at Oak Ridge Atdd, TN (905 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, Oak Ridge Asos, TN, 7 miles east of Oliver Springs, has a last frost 5 days earlier (March 31), a first frost 3 days later (November 4), a season 8 days longer.
When it snows in Oliver Springs, Tennessee
The first measurable snow (0.1 inch or more) in Oliver Springs usually arrives around January 6, and the last of the season around February 12. Those are the middle dates across the winters of 1991–2020 at Oak Ridge Atdd, TN, 7.2 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 52 days after the last snow.
Planting calendar for 37840
| When | What to do |
|---|---|
| January 25 – February 8 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 8 – February 22 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 8 – March 22 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 5 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 9 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 18 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| November 1 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 37840 is 7 miles from Oak Ridge Atdd, TN, which stands at 905 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station; its figures are presented in full for 37830 (Oak Ridge). The 2023 USDA Plant Hardiness Zone Map lists ZIP 37840 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.
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.