Groom climate

Groom Frost Dates and Growing Season

NOAA 1991-2020 normals for Panhandle, 30.5 km from Groom, elevation 3463 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Panhandle. 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 15 and the first fall freeze around October 29, a growing season of about 196 days.

Median at 36°F
last April 26, first October 20
Median at 32°F
last April 15, first October 29
Median at 28°F
last April 3, first November 6

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 8May 4May 1Apr 29Apr 26Apr 23Apr 20Apr 16Apr 11
32°FApr 29Apr 25Apr 21Apr 18Apr 15Apr 11Apr 8Apr 4Mar 31
28°FApr 20Apr 16Apr 10Apr 6Apr 3Mar 31Mar 28Mar 22Mar 14
24°FApr 9Apr 3Mar 31Mar 26Mar 22Mar 17Mar 13Mar 7Mar 2
20°FMar 29Mar 22Mar 16Mar 11Mar 7Mar 4Feb 28Feb 23Feb 16
16°FMar 15Mar 8Mar 4Feb 28Feb 24Feb 19Feb 14Feb 8Jan 29

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 5Oct 11Oct 14Oct 18Oct 20Oct 23Oct 25Oct 27Oct 30
32°FOct 15Oct 20Oct 23Oct 26Oct 29Oct 31Nov 2Nov 5Nov 9
28°FOct 25Oct 30Nov 1Nov 4Nov 6Nov 9Nov 12Nov 16Nov 21
24°FNov 1Nov 6Nov 9Nov 12Nov 15Nov 18Nov 21Nov 25Nov 29
20°FNov 7Nov 13Nov 17Nov 21Nov 24Nov 27Nov 30Dec 4Dec 10
16°FNov 15Nov 23Nov 26Nov 29Dec 2Dec 6Dec 12Dec 18Dec 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°F194187182179176172168163157
32°F216208203200196192187183175
28°F240231225220215211206201194
24°F263254248244238233228221214
20°F287278272267261256251244235
16°F317306298292286280274268258

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
4,087
Cooling degree days, base 65°F
1,579
Growing degree days, base 40°F
7,164
Growing degree days, base 45°F
5,734
Growing degree days, base 50°F
4,459
Growing degree days, base 55°F
3,347
Growing degree days, base 60°F
2,391

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January87008
February690023
March5064106
April27321239
May89122501
June6325769
July1459924
August1409873
September34202619
October22337308
November549178
December846012

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 30.5 km from Groom. 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 USC00416785 (Panhandle). Public domain.