USDA Hardiness Zone 7b
Frost Dates for 74960 — Stilwell, Oklahoma
NOAA 1991–2020 normals from Stilwell 5 NNW, OK (1,000 ft), 6 miles north.
Updated
In Stilwell, the last spring frost (32°F) is around March 31 in half of years and has passed by April 20 in nine years out of ten. The first fall frost comes around November 4, as early as October 21 one year in ten, leaving a typical freeze-free season of 217 days (NOAA, Stilwell 5 NNW, OK).
- Last spring frost
- March 31
- First fall frost
- November 4
- Growing season
- 217 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 12
- Last snow
- February 12
- Winters with snow
- 90%
- Snow per year
- 5.5"
median, 1991–2020
median, 1991–2020
18 of 20 observed
NOAA normal
Frost risk by date in Stilwell
Half of springs at Stilwell 5 NNW, OK see their last 32°F night by March 31; only one in ten is past it by March 10, and one in ten still has one after April 20. Planting tender crops after April 8 leaves a 30% risk of a frost on them, after April 13 20%, and after April 20 10%. The 20 days between the even-odds date and the one-in-ten date is wider than at 92% of the 114 Oklahoma stations behind this site's ZIP pages.
In fall the first 32°F night comes by November 4 in half of years, as early as October 21 one year in ten, and holds off past November 19 one year in ten. A hard freeze of 28°F follows 10 days later, around November 14; in spring the one-in-ten date for 28°F is April 6, 14 days before the 32°F one. The freeze-free season lasts 217 days in a typical year, longer than at 70% of the 114 Oklahoma stations; it reaches 241 days one year in ten and falls short of 192 one year in ten. On average 77 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 16 days longer, to about April 16, and return around October 24. Severe cold of 16°F or below comes in 94% of winters, usually between December 26 and February 1.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Mar 29 | Apr 3 | Apr 8 | Apr 12 | Apr 16 | Apr 20 | Apr 24 | Apr 28 | May 2 |
| 32°F | Mar 10 | Mar 17 | Mar 23 | Mar 28 | Mar 31 | Apr 3 | Apr 8 | Apr 13 | Apr 20 |
| 28°F | Feb 25 | Mar 3 | Mar 8 | Mar 13 | Mar 17 | Mar 21 | Mar 27 | Mar 31 | Apr 6 |
| 24°F | Feb 7 | Feb 16 | Feb 23 | Feb 28 | Mar 4 | Mar 8 | Mar 12 | Mar 17 | Mar 25 |
| 20°F | Jan 23 | Jan 31 | Feb 6 | Feb 12 | Feb 19 | Feb 26 | Mar 3 | Mar 7 | Mar 15 |
| 16°F94% of yrs | Jan 5 | Jan 16 | Jan 23 | Jan 29 | Feb 1 | Feb 8 | Feb 15 | Feb 26 | Mar 6 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 8 | Oct 16 | Oct 19 | Oct 22 | Oct 24 | Oct 26 | Oct 29 | Nov 1 | Nov 6 |
| 32°F | Oct 21 | Oct 26 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 11 | Nov 15 | Nov 19 |
| 28°F | Oct 26 | Nov 2 | Nov 6 | Nov 10 | Nov 14 | Nov 17 | Nov 21 | Nov 26 | Dec 1 |
| 24°F | Nov 7 | Nov 14 | Nov 19 | Nov 25 | Nov 28 | Dec 1 | Dec 4 | Dec 8 | Dec 17 |
| 20°F | Nov 17 | Nov 27 | Dec 1 | Dec 5 | Dec 10 | Dec 16 | Dec 21 | Dec 28 | Jan 4 |
| 16°F94% of yrs | Dec 1 | Dec 7 | Dec 14 | Dec 20 | Dec 26 | Dec 31 | Jan 4 | Jan 11 | Jan 20 |
Freeze probabilities 1991–2020 at Stilwell 5 NNW, OK, 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 74960 →Compare Stilwell with another place →
Weather by month in Stilwell
July is the warmest month at Stilwell 5 NNW, OK, averaging 90°F by day and 68°F at night; January is the coldest at 49°F and 27°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 47% of years.
Warmth for growing adds up to 4,577 growing degree days a year (base 50°F), fewer than at 94% of the 114 Oklahoma stations. 37% of them (1,700) have built up by the end of June, and July adds the most, 897.
| Month | High °F | Low °F | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|
| Jan | 49 | 27 | 100% | 22 | 13 |
| Feb | 54 | 32 | 100% | 14 | 32 |
| Mar | 61 | 39 | 95% | 9 | 125 |
| Apr | 71 | 47 | 47% | 2 | 291 |
| May | 77 | 56 | 2% | 0 | 507 |
| Jun | 85 | 64 | 0% | 0 | 732 |
| Jul | 90 | 68 | 0% | 0 | 897 |
| Aug | 90 | 67 | 0% | 0 | 872 |
| Sep | 83 | 59 | 1% | <1 | 625 |
| Oct | 72 | 49 | 33% | 2 | 342 |
| Nov | 62 | 38 | 98% | 10 | 116 |
| Dec | 50 | 30 | 100% | 19 | 25 |
Monthly normals 1991–2020 at Stilwell 5 NNW, OK (1,000 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, Tahlequah, OK, 19 miles northwest of Stilwell and 150 feet lower, has a last frost 4 days later (April 4), a first frost 4 days earlier (October 31), a season 8 days shorter.
When it snows in Stilwell, Oklahoma
The first measurable snow (0.1 inch or more) in Stilwell usually arrives around January 12, and the last of the season around February 12. Those are the middle dates across the winters of 1991–2020 at Odell 2 N, AR, 13.3 miles away: half of years saw snow earlier, half later. Snow fell in 90% of those winters. The last 32°F night of spring typically comes 47 days after the last snow.
Planting calendar for 74960
| When | What to do |
|---|---|
| January 20 – February 3 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 3 – February 17 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 3 – March 17 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| March 31 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by August 12 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 21 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| November 4 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 74960 is 6 miles from Stilwell 5 NNW, OK, which stands at 1,000 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 2 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 74960 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.