USDA Hardiness Zone 8a
Frost Dates for 74727 — Boswell, Oklahoma
NOAA 1991–2020 normals from Antlers 5NW, OK (578 ft), 17 miles northeast.
Updated
In Boswell, the last spring frost (32°F) is around April 2 in half of years and has passed by April 20 in nine years out of ten. The first fall frost comes around November 1, as early as October 17 one year in ten, leaving a typical freeze-free season of 212 days (NOAA, Antlers 5NW, OK).
- Last spring frost
- April 2
- First fall frost
- November 1
- Growing season
- 212 days
- Hardiness zone
- 8a
50% probability
50% probability
freeze-free, 50%
10 to 15°F (-12.2 to -9.4°C) coldest night
- First snow
- Rare
- Last snow
- Rare
- Winters with snow
- 16%
- Snow per year
- 0.3"
median, 1991–2020
median, 1991–2020
4 of 25 observed
NOAA normal
Frost risk by date in Boswell
Half of springs at Antlers 5NW, OK see their last 32°F night by April 2; only one in ten is past it by March 14, 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 12 20%, and after April 20 10%. The 18 days between the even-odds date and the one-in-ten date is wider than at 60% of the 114 Oklahoma 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 17 one year in ten, and holds off past November 17 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 4, 16 days before the 32°F one. The freeze-free season lasts 212 days in a typical year, longer than at 54% of the 114 Oklahoma stations; it reaches 236 days one year in ten and falls short of 189 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 11 days longer, to about April 13, and return around October 22. Nights of 24°F, cold enough to damage hardier plants, come in 100% of winters and 16°F in 90%.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Mar 29 | Apr 3 | Apr 6 | Apr 9 | Apr 13 | Apr 16 | Apr 20 | Apr 24 | Apr 29 |
| 32°F | Mar 14 | Mar 20 | Mar 26 | Mar 30 | Apr 2 | Apr 4 | Apr 8 | Apr 12 | Apr 20 |
| 28°F | Feb 28 | Mar 6 | Mar 11 | Mar 14 | Mar 18 | Mar 22 | Mar 26 | Mar 31 | Apr 4 |
| 24°F | Feb 11 | Feb 22 | Feb 28 | Mar 3 | Mar 6 | Mar 9 | Mar 13 | Mar 17 | Mar 24 |
| 20°F | Jan 23 | Jan 31 | Feb 6 | Feb 14 | Feb 22 | Feb 27 | Mar 3 | Mar 7 | Mar 12 |
| 16°F90% of yrs | Jan 1 | Jan 13 | Jan 22 | Jan 28 | Feb 3 | Feb 9 | Feb 18 | Feb 28 | Mar 5 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 9 | Oct 14 | Oct 17 | Oct 20 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 5 |
| 32°F | Oct 17 | Oct 21 | Oct 25 | Oct 29 | Nov 1 | Nov 3 | Nov 6 | Nov 11 | Nov 17 |
| 28°F | Oct 26 | Nov 1 | Nov 4 | Nov 7 | Nov 11 | Nov 15 | Nov 19 | Nov 24 | Dec 1 |
| 24°F | Nov 5 | Nov 11 | Nov 16 | Nov 20 | Nov 24 | Nov 29 | Dec 2 | Dec 6 | Dec 14 |
| 20°F | Nov 17 | Nov 25 | Dec 1 | Dec 4 | Dec 8 | Dec 14 | Dec 22 | Dec 29 | Jan 4 |
| 16°F90% of yrs | Dec 1 | Dec 8 | Dec 13 | Dec 20 | Dec 29 | Jan 2 | Jan 7 | Jan 14 | Jan 25 |
Freeze probabilities 1991–2020 at Antlers 5NW, 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 74727 →Compare Boswell with another place →
Weather by month in Boswell
August is the warmest month at Antlers 5NW, OK, averaging 93°F by day and 69°F at night; January is the coldest at 54°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 55% of years.
Warmth for growing adds up to 5,175 growing degree days a year (base 50°F), more than at 58% of the 114 Oklahoma stations. 38% of them (1,989) have built up by the end of June, and August adds the most, 960.
| Month | High °F | Low °F | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|
| Jan | 54 | 29 | 100% | 22 | 24 |
| Feb | 58 | 33 | 100% | 16 | 62 |
| Mar | 66 | 40 | 97% | 8 | 174 |
| Apr | 74 | 48 | 55% | 2 | 334 |
| May | 80 | 58 | 0% | 0 | 586 |
| Jun | 88 | 66 | 0% | 0 | 810 |
| Jul | 93 | 69 | 0% | 0 | 958 |
| Aug | 93 | 69 | 0% | 0 | 960 |
| Sep | 87 | 61 | 0% | 0 | 714 |
| Oct | 75 | 49 | 48% | 1 | 384 |
| Nov | 65 | 39 | 99% | 11 | 136 |
| Dec | 55 | 32 | 100% | 18 | 35 |
Monthly normals 1991–2020 at Antlers 5NW, OK (578 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, Hugo, OK, 19 miles east of Boswell, has a last frost 18 days earlier (March 15), a first frost 14 days later (November 15), a season 32 days longer.
When it snows in Boswell, Oklahoma
Measurable snow is rare here: only 4 of 25 winters from 1991 to 2020 recorded 0.1 inch or more at Antlers, OK, 19.4 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 74727
| When | What to do |
|---|---|
| January 22 – February 5 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| February 5 – February 19 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| March 5 – March 19 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| April 2 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 74727 is 17 miles from Antlers 5NW, OK, which stands at 578 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 74727 in zone 8a, the band where the coldest night of the year averaged 10 to 15°F (-12.2 to -9.4°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.