Hurricane climate

Hurricane Frost Dates and Growing Season

NOAA 1991-2020 normals for La Verkin, 3.4 km from Hurricane, elevation 3194 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for La Verkin. A median date has an even chance of a later freeze in spring, or an earlier one in fall.

The last spring freeze typically comes around April 1 and the first fall freeze around November 5, a growing season of about 217 days.

Median at 36°F
last April 20, first October 27
Median at 32°F
last April 1, first November 5
Median at 28°F
last March 4, first November 15

Last freeze in spring

The chance of a later freeze than the date shown. At 10 percent, one spring in ten still freezes after the date; planting after the 10 percent date for 32°F is the cautious choice.

Threshold10%20%30%40%50%60%70%80%90%
36°FMay 9May 3Apr 29Apr 24Apr 20Apr 15Apr 11Apr 6Mar 30
32°FApr 24Apr 16Apr 10Apr 5Apr 1Mar 27Mar 19Mar 13Mar 5
28°FApr 2Mar 24Mar 13Mar 8Mar 4Feb 28Feb 25Feb 19Feb 12
24°FMar 5Feb 26Feb 21Feb 17Feb 13Feb 9Feb 5Jan 31Jan 23
20°FFeb 16Feb 8Feb 3Jan 31Jan 25Jan 20Jan 11Jan 2Dec 23
16°FFeb 3Jan 24Jan 17Jan 9Jan 3Dec 29Dec 24Dec 17Dec 9

First freeze in fall

The chance of an earlier freeze than the date shown. At 10 percent, one fall in ten freezes before the date.

Threshold10%20%30%40%50%60%70%80%90%
36°FOct 15Oct 19Oct 22Oct 25Oct 27Oct 30Nov 1Nov 4Nov 8
32°FOct 23Oct 28Oct 31Nov 3Nov 5Nov 7Nov 10Nov 13Nov 17
28°FNov 1Nov 5Nov 9Nov 12Nov 15Nov 18Nov 20Nov 24Nov 28
24°FNov 11Nov 16Nov 20Nov 23Nov 26Nov 29Dec 2Dec 6Dec 13
20°FNov 21Nov 27Dec 1Dec 4Dec 8Dec 12Dec 17Dec 22Dec 31
16°FDec 1Dec 6Dec 11Dec 16Dec 21Dec 25Dec 31Jan 5Jan 19

Growing season length

Days between the last spring and first fall freeze at each threshold, with the chance of a season at least that long.

Threshold10%20%30%40%50%60%70%80%90%
36°F212205200194191185180174167
32°F245236229223217211205198190
28°F278272265260254249244234223
24°F316304297291286281275269258
20°F351342335328323315308301291
16°F365365365360353348342335327

How often it gets that cold

The share of years with at least one night at or below each temperature.

36°F or colder
100% of years
32°F or colder
100% of years
28°F or colder
100% of years
24°F or colder
100% of years
20°F or colder
98% of years
16°F or colder
68% of years

Degree days

A degree day is one degree of the daily mean temperature beyond a base, for one day. Heating degree days count cold (the fuel a house burns), cooling degree days heat, growing degree days the warmth a crop needs; each crop has its own base.

Heating degree days, base 65°F
3,440
Cooling degree days, base 65°F
1,944
Growing degree days, base 40°F
7,808
Growing degree days, base 45°F
6,282
Growing degree days, base 50°F
4,952
Growing degree days, base 55°F
3,792
Growing degree days, base 60°F
2,791

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January75502
February554022
March3852134
April21520268
May68141539
June5371816
July05561,021
August0521986
September9288729
October15245366
November505167
December79202

What this means

NOAA computes these from the daily lows at the station over 1991-2020, fitting the dates of each year's last and first freeze to a distribution, so a date can be stated at any level of risk. 36°F is a frost risk for tender plants on a clear, calm night, since the ground cools below the air above it; 32°F is a freeze; 28°F is a hard freeze that kills most annuals.

The station is 3.4 km from Hurricane. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

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Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00424968 (La Verkin). Public domain.