Frost dates / Oklahoma / Norman

Frost dates in Norman, OK

The station on this page is NORMAN 3SSE, OK US (USC00346386), 6.7 miles from the city point. Population in the Census 2024 estimate is 131,010.

Zone 7bUSDA average annual extreme minimum 5°F to 10°F, from ZIP 73071 (3.5 miles from the city point used on this page).

Median last 32°F is April 3. Median first 32°F is November 3. The 50% growing-season length is 212 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 19	Earlier date. A last 32°F on or after this day is common.
50%	April 3	Median.
10%	April 18	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 21	Earlier date. A first 32°F on or before this day is uncommon.
50%	November 3	Median.
90%	November 17	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%	234
50%	212
90%	191

28°F threshold

	10%	50%	90%
Last, on or after	April 7	March 23	March 5
First, on or before	October 27	November 12	November 27
Season at least	256 days	232 days	211 days

36°F threshold

	10%	50%	90%
Last, on or after	April 28	April 14	March 30
First, on or before	October 11	October 25	November 6
Season at least	212 days	193 days	173 days

Station NORMAN 3SSE, OK US (USC00346386). Completeness flag R, 20 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 343.8 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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Norman, 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: NORMAN 3SSE, OK US (USC00346386), 6.7 miles. Median last 32°F April 3. Median first 32°F November 3. The 50% growing-season length is 212 days.

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32°F probabilities at this station

	10%	50%	90%
Last 32°F on or after	April 18	April 3	March 19
First 32°F on or before	October 21	November 3	November 17

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.

Date checks use your device’s calendar and appear after the page loads.