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USDA Hardiness Zone 7b

Frost Dates for 73015 — Carnegie, Oklahoma

NOAA 1991–2020 normals from Carnegie 5 NE, OK (1,481 ft), 4 miles north.

Updated

In Carnegie, the last spring frost (32°F) is around April 6 in half of years and has passed by April 22 in nine years out of ten. The first fall frost comes around October 31, as early as October 15 one year in ten, leaving a typical freeze-free season of 206 days (NOAA, Carnegie 5 NE, OK).

Last spring frost
April 6

50% probability

First fall frost
October 31

50% probability

Growing season
206 days

freeze-free, 50%

Hardiness zone
7b

5 to 10°F (-15.0 to -12.2°C) coldest night

First snow
December 30

median, 1991–2020

Last snow
February 7

median, 1991–2020

Winters with snow
100%

15 of 15 observed

Snow per year
—

NOAA normal

Frost risk by date in Carnegie

Half of springs at Carnegie 5 NE, OK see their last 32°F night by April 6; only one in ten is past it by March 20, and one in ten still has one after April 22. Planting tender crops after April 12 leaves a 30% risk of a frost on them, after April 18 20%, and after April 22 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 31 in half of years, as early as October 15 one year in ten, and holds off past November 14 one year in ten. A hard freeze of 28°F follows 9 days later, around November 9; in spring the one-in-ten date for 28°F is April 11, 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 230 days one year in ten and falls short of 183 one year in ten. On average 80 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 10 days longer, to about April 16, and return around October 23. Severe cold of 16°F or below comes in 98% of winters, usually between December 15 and February 15.

Spring: the chance of another night this cold after the date
Low90%80%70%60%50%40%30%20%10%
36°FApr 2Apr 6Apr 10Apr 13Apr 16Apr 19Apr 22Apr 26Apr 30
32°FMar 20Mar 26Mar 31Apr 3Apr 6Apr 9Apr 12Apr 18Apr 22
28°FMar 4Mar 11Mar 16Mar 21Mar 25Mar 29Apr 2Apr 6Apr 11
24°FFeb 22Feb 28Mar 3Mar 6Mar 10Mar 14Mar 18Mar 24Mar 31
20°FFeb 4Feb 15Feb 20Feb 24Feb 28Mar 2Mar 5Mar 11Mar 16
16°F98% of yrsJan 16Jan 28Feb 3Feb 10Feb 15Feb 20Feb 25Mar 1Mar 7
Fall: the chance the first night this cold has come by the date
Low10%20%30%40%50%60%70%80%90%
36°FOct 9Oct 15Oct 18Oct 20Oct 23Oct 25Oct 28Oct 31Nov 4
32°FOct 15Oct 21Oct 25Oct 28Oct 31Nov 3Nov 5Nov 9Nov 14
28°FOct 24Oct 31Nov 3Nov 6Nov 9Nov 12Nov 15Nov 20Nov 26
24°FNov 1Nov 6Nov 11Nov 15Nov 20Nov 24Nov 27Dec 1Dec 7
20°FNov 9Nov 18Nov 24Nov 27Dec 1Dec 4Dec 10Dec 15Dec 21
16°F98% of yrsNov 23Nov 30Dec 4Dec 10Dec 15Dec 19Dec 25Jan 2Jan 12

Freeze probabilities 1991–2020 at Carnegie 5 NE, 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 73015 →Compare Carnegie with another place →

Weather by month in Carnegie

July is the warmest month at Carnegie 5 NE, OK, averaging 94°F by day and 71°F at night; January is the coldest at 51°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 5,148 growing degree days a year (base 50°F), more than at 51% of the 114 Oklahoma stations. 38% of them (1,934) have built up by the end of June, and July adds the most, 1,014.

Monthly normals 1991–2020 at Carnegie 5 NE, OK
MonthHigh °FLow °F32°F nightNights ≤ 32°FGDD 50°F
Jan5126100%2412
Feb5529100%1528
Mar633899%9128
Apr724766%2304
May81583%0605
Jun89680%0858
Jul94710%01014
Aug94700%0982
Sep86620%0718
Oct754951%1373
Nov623799%9110
Dec5128100%2017

Monthly normals 1991–2020 at Carnegie 5 NE, OK (1,481 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, Apache 4ENE Mesonet, OK, 22 miles southeast of Carnegie, has a last frost 3 days earlier (April 3), a first frost 3 days later (November 3), a season 7 days longer.

Frost dates for 73538 (Elgin) →

When it snows in Carnegie, Oklahoma

The first measurable snow (0.1 inch or more) in Carnegie usually arrives around December 30, and the last of the season around February 7. Those are the middle dates across the winters of 1991–2020 at Carnegie 5 NE, OK, 4.3 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 58 days after the last snow.

Planting calendar for 73015

What to do and when, from the 50% frost dates for Carnegie, Oklahoma
WhenWhat to do
January 26 – February 9Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out.
February 9 – February 23Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early.
March 9 – March 23Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil.
April 6 onwardTransplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast.
by August 8Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops.
by October 17Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation.
October 31 onwardPlant 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 73015 is 4 miles from Carnegie 5 NE, OK, which stands at 1,481 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 73015 in zone 7b, the band where the coldest night of the year averaged 5 to 10°F (-15.0 to -12.2°C) over 1991–2020; a zone describes winter lows, not frost dates.

Frost dates across Oklahoma →

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.

Other zone 7b places in Oklahoma