USDA Hardiness Zone 8a
Frost Dates for 74730 — Calera, Oklahoma
NOAA 1991–2020 normals from Durant, OK (600 ft), 7 miles northeast.
Updated
In Calera, the last spring frost (32°F) is around March 31 in half of years and has passed by April 19 in nine years out of ten. The first fall frost comes around November 5, as early as October 22 one year in ten, leaving a typical freeze-free season of 221 days (NOAA, Durant, OK).
- Last spring frost
- March 31
- First fall frost
- November 5
- Growing season
- 221 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
- 41%
- Snow per year
- 2"
median, 1991–2020
median, 1991–2020
7 of 17 observed
NOAA normal
Frost risk by date in Calera
Half of springs at Durant, 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 19. Planting tender crops after April 7 leaves a 30% risk of a frost on them, after April 13 20%, and after April 19 10%. The 19 days between the even-odds date and the one-in-ten date is wider than at 81% of the 114 Oklahoma stations behind this site's ZIP pages.
In fall the first 32°F night comes by November 5 in half of years, as early as October 22 one year in ten, and holds off past November 23 one year in ten. A hard freeze of 28°F follows 12 days later, around November 17; in spring the one-in-ten date for 28°F is April 3, 16 days before the 32°F one. The freeze-free season lasts 221 days in a typical year, longer than at 80% of the 114 Oklahoma stations; it reaches 247 days one year in ten and falls short of 195 one year in ten. On average 70 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 11, and return around October 28. Nights of 24°F, cold enough to damage hardier plants, come in 100% of winters and 16°F in 85%.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Mar 24 | Apr 1 | Apr 5 | Apr 8 | Apr 11 | Apr 15 | Apr 18 | Apr 22 | Apr 26 |
| 32°F | Mar 10 | Mar 15 | Mar 21 | Mar 26 | Mar 31 | Apr 4 | Apr 7 | Apr 13 | Apr 19 |
| 28°F | Feb 23 | Mar 1 | Mar 5 | Mar 9 | Mar 13 | Mar 17 | Mar 22 | Mar 28 | Apr 3 |
| 24°F | Feb 6 | Feb 15 | Feb 22 | Feb 26 | Mar 1 | Mar 4 | Mar 8 | Mar 12 | Mar 18 |
| 20°F99% of yrs | Jan 17 | Jan 29 | Feb 3 | Feb 10 | Feb 15 | Feb 21 | Feb 27 | Mar 3 | Mar 9 |
| 16°F85% of yrs | Dec 28 | Jan 9 | Jan 20 | Jan 26 | Feb 1 | Feb 5 | Feb 11 | Feb 19 | Feb 28 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Oct 13 | Oct 19 | Oct 22 | Oct 26 | Oct 28 | Oct 31 | Nov 2 | Nov 5 | Nov 9 |
| 32°F | Oct 22 | Oct 28 | Oct 31 | Nov 2 | Nov 5 | Nov 8 | Nov 11 | Nov 17 | Nov 23 |
| 28°F | Oct 31 | Nov 5 | Nov 8 | Nov 12 | Nov 17 | Nov 20 | Nov 25 | Nov 29 | Dec 4 |
| 24°F | Nov 9 | Nov 16 | Nov 22 | Nov 26 | Nov 30 | Dec 3 | Dec 6 | Dec 12 | Dec 20 |
| 20°F99% of yrs | Nov 23 | Nov 30 | Dec 4 | Dec 8 | Dec 13 | Dec 20 | Dec 28 | Jan 4 | Jan 14 |
| 16°F85% of yrs | Dec 3 | Dec 10 | Dec 15 | Dec 22 | Dec 31 | Jan 5 | Jan 11 | Jan 21 | Feb 4 |
Freeze probabilities 1991–2020 at Durant, 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 74730 →Compare Calera with another place →
Weather by month in Calera
August is the warmest month at Durant, OK, averaging 95°F by day and 70°F at night; January is the coldest at 54°F and 30°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 48% of years.
Warmth for growing adds up to 5,585 growing degree days a year (base 50°F), more than at 93% of the 114 Oklahoma stations. 39% of them (2,155) have built up by the end of June, and August adds the most, 1,015. Precipitation totals 44.2 inches a year, most in May (5.4") and least in August (2.4"); May to September bring 45% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 54 | 30 | 2.5 | 100% | 21 | 36 |
| Feb | 59 | 34 | 2.6 | 100% | 14 | 65 |
| Mar | 67 | 42 | 4.0 | 94% | 6 | 205 |
| Apr | 75 | 49 | 3.9 | 48% | 1 | 359 |
| May | 81 | 59 | 5.4 | 0% | 0 | 628 |
| Jun | 89 | 68 | 5.1 | 0% | 0 | 862 |
| Jul | 94 | 71 | 3.3 | 0% | 0 | 1011 |
| Aug | 95 | 70 | 2.4 | 0% | 0 | 1015 |
| Sep | 88 | 62 | 3.8 | 0% | 0 | 747 |
| Oct | 78 | 51 | 4.4 | 32% | 1 | 447 |
| Nov | 66 | 40 | 3.5 | 97% | 9 | 166 |
| Dec | 56 | 32 | 3.3 | 100% | 18 | 45 |
Monthly normals 1991–2020 at Durant, OK (600 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, Durant 6SSE Mesonet, OK, 7 miles east of Calera, has a last frost 12 days earlier (March 19), a first frost 7 days later (November 12), a season 16 days longer.
When it snows in Calera, Oklahoma
Measurable snow is rare here: only 7 of 17 winters from 1991 to 2020 recorded 0.1 inch or more at Durant, OK, 6.9 miles away, so there is no typical first-snow date to plan around.
Planting calendar for 74730
| 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 13 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by October 22 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| November 5 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 74730 is 7 miles from Durant, OK, which stands at 600 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station; its figures are presented in full for 74701 (Durant). The 2023 USDA Plant Hardiness Zone Map lists ZIP 74730 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.