Coldwater climate

Coldwater Frost Dates and Growing Season

NOAA 1991-2020 normals for Coldwater, 0.5 km from Coldwater, elevation 2115 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Coldwater. 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 13 and the first fall freeze around October 27, a growing season of about 197 days.

Median at 36°F
last April 22, first October 18
Median at 32°F
last April 13, first October 27
Median at 28°F
last April 3, first November 5

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 6May 1Apr 28Apr 25Apr 22Apr 19Apr 17Apr 14Apr 8
32°FApr 28Apr 23Apr 19Apr 16Apr 13Apr 9Apr 6Apr 3Mar 29
28°FApr 18Apr 13Apr 9Apr 6Apr 3Mar 31Mar 28Mar 23Mar 17
24°FApr 8Apr 3Mar 31Mar 27Mar 23Mar 19Mar 14Mar 10Mar 5
20°FMar 31Mar 25Mar 20Mar 15Mar 11Mar 8Mar 4Mar 1Feb 24
16°FMar 20Mar 13Mar 9Mar 5Mar 2Feb 28Feb 22Feb 18Feb 10

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 3Oct 9Oct 13Oct 16Oct 18Oct 20Oct 23Oct 26Oct 31
32°FOct 14Oct 18Oct 21Oct 24Oct 27Oct 30Nov 2Nov 4Nov 9
28°FOct 21Oct 26Oct 31Nov 2Nov 5Nov 8Nov 11Nov 15Nov 19
24°FOct 31Nov 4Nov 7Nov 11Nov 14Nov 17Nov 20Nov 24Nov 29
20°FNov 5Nov 11Nov 16Nov 19Nov 23Nov 26Nov 30Dec 4Dec 10
16°FNov 14Nov 21Nov 25Nov 29Dec 2Dec 5Dec 9Dec 16Dec 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°F196190185181177174170165157
32°F218210205201197193188183175
28°F238231224219215211207202194
24°F258252245239234230224218211
20°F278271264259254249243237229
16°F302292285280274270264257247

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
3,942
Cooling degree days, base 65°F
1,905
Growing degree days, base 40°F
7,645
Growing degree days, base 45°F
6,207
Growing degree days, base 50°F
4,916
Growing degree days, base 55°F
3,772
Growing degree days, base 60°F
2,769

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January88008
February695030
March4879131
April23341290
May65159561
June3371817
July1529993
August0475939
September25257683
October19060357
November517496
December848011

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 0.5 km from Coldwater. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00141704 (Coldwater). Public domain.