Grant County climate

Grant County Frost Dates and Growing Season

NOAA 1991-2020 normals for Ulysses 3NE, 4.3 km from Grant County, elevation 3094 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Ulysses 3NE. 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 28 and the first fall freeze around October 16, a growing season of about 171 days.

Median at 36°F
last May 6, first October 6
Median at 32°F
last April 28, first October 16
Median at 28°F
last April 16, first October 24

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 19May 15May 12May 9May 6May 4May 1Apr 30Apr 24
32°FMay 10May 5May 2Apr 30Apr 28Apr 25Apr 21Apr 17Apr 12
28°FMay 1Apr 27Apr 23Apr 20Apr 16Apr 13Apr 10Apr 7Apr 2
24°FApr 22Apr 16Apr 12Apr 8Apr 6Apr 3Mar 31Mar 27Mar 19
20°FApr 11Apr 6Apr 2Mar 31Mar 26Mar 22Mar 17Mar 13Mar 8
16°FApr 3Mar 28Mar 23Mar 17Mar 13Mar 9Mar 6Mar 3Feb 27

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 24Sep 29Oct 1Oct 4Oct 6Oct 9Oct 12Oct 15Oct 19
32°FOct 2Oct 6Oct 9Oct 13Oct 16Oct 18Oct 20Oct 23Oct 27
28°FOct 11Oct 16Oct 19Oct 21Oct 24Oct 26Oct 29Nov 1Nov 5
24°FOct 19Oct 23Oct 27Oct 30Nov 1Nov 3Nov 6Nov 9Nov 14
20°FOct 27Nov 1Nov 4Nov 7Nov 10Nov 12Nov 16Nov 19Nov 24
16°FNov 1Nov 7Nov 11Nov 15Nov 18Nov 21Nov 24Nov 28Dec 3

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°F170164159155152149145140134
32°F188182178174171166163158152
28°F209202197193189185181177169
24°F229223218214209205201196189
20°F252244239234229225220214207
16°F272264259254249245240232223

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
5,263
Cooling degree days, base 65°F
1,286
Growing degree days, base 40°F
6,159
Growing degree days, base 45°F
4,900
Growing degree days, base 50°F
3,792
Growing degree days, base 55°F
2,826
Growing degree days, base 60°F
1,993

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,05701
February85306
March670049
April3958153
May14975402
June13271708
July2408871
August3347809
September62158549
October33719210
November699033
December1,02302

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 4.3 km from Grant County. 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 USC00148287 (Ulysses 3NE). Public domain.