Frost Dates for 74074 — Stillwater, Oklahoma

Half of springs at Stillwater 2 W, OK see their last 32°F night by April 5; only one in ten is past it by March 21, and one in ten still has one after April 21. Planting tender crops after April 12 leaves a 30% risk of a frost on them, after April 16 20%, and after April 21 10%. The 16 days between the even-odds date and the one-in-ten date is narrower than at 61% of the 114 Oklahoma stations behind this site's ZIP pages.

In fall the first 32°F night comes by October 30 in half of years, as early as October 16 one year in ten, and holds off past November 15 one year in ten. A hard freeze of 28°F follows 10 days later, around November 9; in spring the one-in-ten date for 28°F is April 10, 11 days before the 32°F one. The freeze-free season lasts 206 days in a typical year, shorter than at 71% of the 114 Oklahoma stations; it reaches 227 days one year in ten and falls short of 184 one year in ten. On average 88 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 22. Severe cold of 16°F or below comes every winter, usually between December 12 and February 20.

July is the warmest month at Stillwater 2 W, OK, averaging 94°F by day and 71°F at night; January is the coldest at 49°F and 26°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 66% of years.

Warmth for growing adds up to 5,052 growing degree days a year (base 50°F), fewer than at 66% of the 114 Oklahoma stations. 38% of them (1,909) have built up by the end of June, and July adds the most, 1,007. Precipitation totals 36.1 inches a year, most in May (4.7") and least in January (1.3"); May to September bring 53% of it.

The nearest other station, Stillwater Regional Airport, OK, 4 miles north of Stillwater, has a last frost 2 days earlier (April 3), a first frost 1 day later (October 31), a season 3 days longer.

The first measurable snow (0.1 inch or more) in Stillwater usually arrives around December 12, and the last of the season around February 27. Those are the middle dates across the winters of 1991–2020 at Stillwater 2 W, OK, 1.3 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 37 days after the last snow.

ZIP 74074 is 1 mile from Stillwater 2 W, OK, which stands at 890 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 74074 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.