Alvord climate

Alvord Frost Dates and Growing Season

NOAA 1991-2020 normals for Alvord 3 N, 3.8 km from Alvord, elevation 1010 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Alvord 3 N. 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 4, a growing season of about 219 days.

Median at 36°F
last April 12, first October 27
Median at 32°F
last April 1, first November 4
Median at 28°F
last March 18, first November 13

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°FApr 30Apr 24Apr 20Apr 16Apr 12Apr 8Apr 5Apr 1Mar 26
32°FApr 21Apr 14Apr 7Apr 4Apr 1Mar 28Mar 24Mar 18Mar 12
28°FApr 6Mar 31Mar 27Mar 23Mar 18Mar 15Mar 10Mar 5Feb 27
24°FMar 27Mar 19Mar 15Mar 11Mar 7Mar 3Feb 28Feb 23Feb 15
20°FMar 16Mar 9Mar 3Feb 28Feb 22Feb 16Feb 8Jan 31Jan 20
16°FMar 6Feb 25Feb 16Feb 7Feb 1Jan 26Jan 19Jan 6Dec 25

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 14Oct 18Oct 21Oct 24Oct 27Oct 30Nov 2Nov 5Nov 9
32°FOct 20Oct 26Oct 30Nov 1Nov 4Nov 6Nov 9Nov 15Nov 22
28°FOct 28Nov 3Nov 6Nov 9Nov 13Nov 17Nov 21Nov 26Dec 1
24°FNov 5Nov 11Nov 16Nov 21Nov 25Nov 29Dec 2Dec 7Dec 15
20°FNov 16Nov 25Nov 29Dec 3Dec 7Dec 11Dec 18Dec 27Jan 5
16°FNov 29Dec 5Dec 10Dec 16Dec 22Dec 29Jan 4Jan 11Jan 25

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°F220212207203198194189182175
32°F245235229224219215210204195
28°F269259250245240235229222214
24°F294284277271265259252244235
20°F331317307300293285278270258
16°F365352342335327318307299287

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
99% of years
16°F or colder
91% 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
2,862
Cooling degree days, base 65°F
2,353
Growing degree days, base 40°F
8,851
Growing degree days, base 45°F
7,270
Growing degree days, base 50°F
5,823
Growing degree days, base 55°F
4,515
Growing degree days, base 60°F
3,358

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January702141
February514485
March34322214
April13678403
May26226665
June0445895
July05721,037
August05591,024
September9326766
October122104456
November36514178
December645258

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 3.8 km from Alvord. 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 USC00410206 (Alvord 3 N). Public domain.