Galva climate

Galva Frost Dates and Growing Season

NOAA 1991-2020 normals for Galva, 0.9 km from Galva, elevation 810 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Galva. 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 12, a growing season of about 166 days.

Median at 36°F
last May 5, first October 2
Median at 32°F
last April 26, first October 12
Median at 28°F
last April 16, first October 22

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 20May 15May 12May 8May 5May 3Apr 30Apr 27Apr 23
32°FMay 11May 5May 2Apr 29Apr 26Apr 24Apr 21Apr 17Apr 12
28°FApr 30Apr 25Apr 22Apr 19Apr 16Apr 12Apr 9Apr 6Apr 3
24°FApr 20Apr 15Apr 11Apr 8Apr 5Apr 3Apr 1Mar 28Mar 23
20°FApr 9Apr 4Apr 2Mar 31Mar 27Mar 23Mar 19Mar 15Mar 9
16°FMar 31Mar 27Mar 23Mar 19Mar 15Mar 13Mar 9Mar 6Mar 1

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 17Sep 23Sep 27Sep 30Oct 2Oct 4Oct 7Oct 10Oct 13
32°FSep 25Oct 2Oct 6Oct 10Oct 12Oct 14Oct 16Oct 19Oct 24
28°FOct 7Oct 13Oct 17Oct 20Oct 22Oct 24Oct 27Oct 30Nov 3
24°FOct 20Oct 24Oct 28Oct 30Nov 1Nov 3Nov 7Nov 10Nov 15
20°FOct 31Nov 3Nov 6Nov 9Nov 12Nov 14Nov 17Nov 21Nov 27
16°FNov 7Nov 11Nov 15Nov 18Nov 21Nov 24Nov 28Dec 1Dec 7

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°F165160156152148144140134127
32°F186179175171166162158152145
28°F207201196192189184180175166
24°F231223218214210206202197189
20°F255246241235231226222216210
16°F273265260255250245241236229

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
6,470
Cooling degree days, base 65°F
839
Growing degree days, base 40°F
5,263
Growing degree days, base 45°F
4,133
Growing degree days, base 50°F
3,123
Growing degree days, base 55°F
2,231
Growing degree days, base 60°F
1,467

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,35000
February1,09302
March848229
April4697114
May17766366
June23193620
July5269728
August13207659
September11585424
October41312155
November792025
December1,17002

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 0.9 km from Galva. 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 USC00113335 (Galva). Public domain.