Frost Dates for 74653 — Tonkawa, Oklahoma

Half of springs at Blackwell 4SSE Mesonet, OK see their last 32°F night by April 8; only one in ten is past it by March 22, and one in ten still has one after April 24. Planting tender crops after April 14 leaves a 30% risk of a frost on them, after April 18 20%, and after April 24 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 27 in half of years, as early as October 12 one year in ten, and holds off past November 10 one year in ten. A hard freeze of 28°F follows 9 days later, around November 5; in spring the one-in-ten date for 28°F is April 14, 10 days before the 32°F one. The freeze-free season lasts 201 days in a typical year, shorter than at 83% of the 114 Oklahoma stations; it reaches 222 days one year in ten and falls short of 180 one year in ten. On average 101 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 19, and return around October 18. Severe cold of 16°F or below comes every winter, usually between December 7 and February 23.

July is the warmest month at Blackwell 4SSE Mesonet, OK, averaging 93°F by day and 70°F at night; January is the coldest at 47°F and 23°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 72% of years.

Warmth for growing adds up to 4,729 growing degree days a year (base 50°F), fewer than at 91% of the 114 Oklahoma stations. 37% of them (1,768) have built up by the end of June, and July adds the most, 975.

The nearest other station, Blackwell 1SSW, OK, 8 miles north of Tonkawa, has a last frost 4 days later (April 12), a first frost 2 days later (October 29), a season 2 days shorter.

The first measurable snow (0.1 inch or more) in Tonkawa usually arrives around December 22, and the last of the season around February 25. Those are the middle dates across the winters of 1991–2020 at Blackwell 1SSW, OK, 8.4 miles away: half of years saw snow earlier, half later. Snow fell in 95% of those winters. The last 32°F night of spring typically comes 42 days after the last snow.

ZIP 74653 is 7 miles from Blackwell 4SSE Mesonet, OK, which stands at 997 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 74653 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.