Wadsworth climate

Wadsworth Frost Dates and Growing Season

NOAA 1991-2020 normals for Chippewa Lake, 17.5 km from Wadsworth, elevation 1180 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Chippewa Lake. 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 29 and the first fall freeze around October 19, a growing season of about 172 days.

Median at 36°F
last May 8, first October 8
Median at 32°F
last April 29, first October 19
Median at 28°F
last April 17, first November 1

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 19May 15May 11May 8May 5May 2Apr 30Apr 25
32°FMay 15May 9May 5May 2Apr 29Apr 25Apr 22Apr 19Apr 15
28°FMay 3Apr 29Apr 23Apr 20Apr 17Apr 15Apr 11Apr 7Apr 3
24°FApr 20Apr 15Apr 11Apr 7Apr 5Apr 2Mar 31Mar 29Mar 23
20°FApr 9Apr 4Apr 1Mar 31Mar 28Mar 25Mar 22Mar 18Mar 13
16°FApr 1Mar 29Mar 25Mar 21Mar 18Mar 15Mar 13Mar 8Mar 3

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 11Oct 13Oct 16Oct 21
32°FOct 5Oct 11Oct 14Oct 17Oct 19Oct 22Oct 25Oct 28Nov 1
28°FOct 17Oct 22Oct 25Oct 29Nov 1Nov 2Nov 5Nov 8Nov 13
24°FOct 30Nov 3Nov 6Nov 9Nov 12Nov 15Nov 18Nov 22Nov 29
20°FNov 9Nov 12Nov 16Nov 19Nov 22Nov 26Dec 1Dec 3Dec 8
16°FNov 17Nov 23Nov 26Nov 30Dec 3Dec 6Dec 10Dec 15Dec 21

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°F170163158153150146141138131
32°F191185180176172167163158152
28°F217209204199195191187182174
24°F239232227223220216212207200
20°F263255250245240236232228220
16°F284276271265261256250245237

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
6,526
Cooling degree days, base 65°F
582
Growing degree days, base 40°F
4,812
Growing degree days, base 45°F
3,688
Growing degree days, base 50°F
2,703
Growing degree days, base 55°F
1,851
Growing degree days, base 60°F
1,139

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,25502
February1,08102
March920123
April531489
May25134272
June58122515
July12193646
August19160606
September12161394
October4357130
November755022
December1,08903

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 17.5 km from Wadsworth. 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 USC00331541 (Chippewa Lake). Public domain.