Jal climate

Jal Frost Dates and Growing Season

NOAA 1991-2020 normals for Jal, 0.6 km from Jal, elevation 3054 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Jal. 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 March 31 and the first fall freeze around November 3, a growing season of about 215 days.

Median at 36°F
last April 13, first October 24
Median at 32°F
last March 31, first November 3
Median at 28°F
last March 16, 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°FMay 3Apr 26Apr 21Apr 18Apr 13Apr 10Apr 6Apr 3Mar 29
32°FApr 19Apr 11Apr 7Apr 3Mar 31Mar 28Mar 23Mar 19Mar 12
28°FApr 4Mar 30Mar 25Mar 20Mar 16Mar 12Mar 8Mar 4Feb 28
24°FMar 25Mar 15Mar 10Mar 6Mar 3Feb 28Feb 25Feb 19Feb 11
20°FMar 9Mar 2Feb 27Feb 22Feb 16Feb 9Feb 3Jan 28Jan 19
16°FFeb 27Feb 16Feb 8Feb 1Jan 26Jan 18Jan 12Jan 5Dec 26

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 11Oct 17Oct 19Oct 22Oct 24Oct 27Oct 31Nov 2Nov 7
32°FOct 19Oct 23Oct 27Oct 31Nov 3Nov 6Nov 8Nov 12Nov 17
28°FOct 28Nov 2Nov 6Nov 10Nov 13Nov 17Nov 20Nov 24Nov 30
24°FNov 7Nov 13Nov 17Nov 21Nov 25Nov 28Dec 1Dec 4Dec 9
20°FNov 18Nov 25Nov 30Dec 2Dec 5Dec 9Dec 13Dec 19Dec 25
16°FNov 29Dec 4Dec 9Dec 15Dec 20Dec 24Dec 29Jan 4Jan 16

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°F213205200196192187182177170
32°F239230225220215209204198191
28°F265257251246240234229223214
24°F290281275271266261256249238
20°F322312305299292285280273263
16°F358349342334327318310302290

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
100% of years
16°F or colder
93% 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
2,701
Cooling degree days, base 65°F
2,147
Growing degree days, base 40°F
8,705
Growing degree days, base 45°F
7,073
Growing degree days, base 50°F
5,591
Growing degree days, base 55°F
4,281
Growing degree days, base 60°F
3,134

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January666021
February478158
March3079210
April9770428
May21245690
June1451900
July0529994
August0496961
September11274713
October10167438
November3715152
December648027

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 0.6 km from Jal. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00294346 (Jal). Public domain.