Warm Springs climate

Warm Springs Frost Dates and Growing Season

NOAA 1991-2020 normals for Hot Springs, 6.3 km from Warm Springs, elevation 2244 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Hot Springs. 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 26 and the first fall freeze around October 19, a growing season of about 173 days.

Median at 36°F
last May 9, first October 8
Median at 32°F
last April 26, first October 19
Median at 28°F
last April 12, first October 30

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 25May 20May 16May 13May 9May 6May 3Apr 30Apr 23
32°FMay 15May 9May 4Apr 30Apr 26Apr 22Apr 19Apr 16Apr 12
28°FMay 2Apr 22Apr 18Apr 15Apr 12Apr 9Apr 6Apr 2Mar 29
24°FApr 12Apr 7Apr 3Apr 1Mar 30Mar 27Mar 22Mar 18Mar 13
20°FMar 31Mar 27Mar 22Mar 18Mar 16Mar 12Mar 9Mar 4Feb 27
16°FMar 22Mar 16Mar 12Mar 7Mar 3Feb 28Feb 26Feb 20Feb 11

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°FSep 25Sep 30Oct 3Oct 5Oct 8Oct 10Oct 13Oct 17Oct 21
32°FOct 5Oct 9Oct 13Oct 15Oct 19Oct 22Oct 25Oct 29Nov 1
28°FOct 14Oct 21Oct 24Oct 28Oct 30Nov 1Nov 3Nov 7Nov 12
24°FOct 28Nov 1Nov 3Nov 6Nov 9Nov 12Nov 16Nov 20Nov 27
20°FNov 3Nov 9Nov 13Nov 17Nov 22Nov 26Dec 1Dec 5Dec 13
16°FNov 15Nov 23Nov 28Dec 1Dec 6Dec 10Dec 16Dec 21Dec 27

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°F173166161156152148143137130
32°F196189183178173168163158150
28°F220213208203200195191185175
24°F247239233229225221217211204
20°F276267261256250245240234225
16°F304295288282276271265259251

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
100% 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
5,491
Cooling degree days, base 65°F
576
Growing degree days, base 40°F
5,194
Growing degree days, base 45°F
3,958
Growing degree days, base 50°F
2,878
Growing degree days, base 55°F
1,949
Growing degree days, base 60°F
1,180

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,06504
February88205
March744031
April4105136
May18734325
June38116528
July7197656
August12160612
September10858403
October3935144
November689027
December95607

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 6.3 km from Warm Springs. 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 USC00444128 (Hot Springs). Public domain.