Frost dates / Oklahoma / Owasso

Frost dates in Owasso, OK

The station on this page is TULSA INTL AP, OK US (USW00013968), 6.7 miles from the city point. Population in the Census 2024 estimate is 42,821.

Zone 7bUSDA average annual extreme minimum 5°F to 10°F, from ZIP 74055 (1.2 miles from the city point used on this page).

Median last 32°F is March 31. Median first 32°F is November 4. The 50% growing-season length is 220 days. The green band runs from the median last frost to the median first frost. Thin ticks mark the 10%, 50%, and 90% dates.

Outside the median season Growing seasonTicks: 10%, 50%, and 90%

Last 32°F in spring

NCEI’s probability is the chance the last spring minimum of 32°F or lower occurs on or after the date.

Probability	Date	How to read it
90%	March 11	Earlier date. A last 32°F on or after this day is common.
50%	March 31	Median.
10%	April 15	Later date. A last 32°F on or after this day is uncommon.

First 32°F in fall

NCEI’s probability is the chance the first autumn minimum of 32°F or lower occurs on or before the date.

Probability	Date	How to read it
10%	October 20	Earlier date. A first 32°F on or before this day is uncommon.
50%	November 4	Median.
90%	November 19	Later date. A first 32°F on or before this day is common.

32°F growing-season length

Days between the last spring 32°F and the first autumn 32°F. The figure is a length the season meets or exceeds at that probability, from NCEI, not a subtraction done on this site.

Probability the season is at least this long	Days
10%	243
50%	220
90%	198

28°F threshold

	10%	50%	90%
Last, on or after	April 5	March 17	February 28
First, on or before	October 31	November 13	December 1
Season at least	268 days	242 days	217 days

36°F threshold

	10%	50%	90%
Last, on or after	April 27	April 10	March 26
First, on or before	October 11	October 26	November 6
Season at least	221 days	198 days	176 days

Station TULSA INTL AP, OK US (USW00013968). Completeness flag S, 29 years used for the 32°F dates. NCEI’s annual probability of at least one day at or below 32°F is 100%. Freeze dates are conditional on that threshold occurring. Elevation 198.1 m. The same probability language applies to the 28°F and 36°F rows when those dates passed the same quality checks.

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Owasso, OK

Zone 7bAverage annual extreme minimum 5°F to 10°F

Outside the median season Growing seasonTicks: 10%, 50%, and 90%

Oklahoma. Nearest qualified station: TULSA INTL AP, OK US (USW00013968), 6.7 miles. Median last 32°F March 31. Median first 32°F November 4. The 50% growing-season length is 220 days.

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32°F probabilities at this station

	10%	50%	90%
Last 32°F on or after	April 15	March 31	March 11
First 32°F on or before	October 20	November 4	November 19

Column order matches the NCEI file: for the last freeze, 10% is the later date and 90% is the earlier date. How to read the probabilities.

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Planting calendar

Frost dates for Oklahoma are above. Planting windows appear for states with a cited extension guide. The fall and seed tools use the numbers you enter and the station dates.

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