Coloma climate

Coloma Frost Dates and Growing Season

NOAA 1991-2020 normals for Georgetown RS, 16.7 km from Coloma, elevation 3001 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Georgetown RS. 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 12 and the first fall freeze around November 21, a growing season of about 221 days.

Median at 36°F
last May 1, first November 3
Median at 32°F
last April 12, first November 21
Median at 28°F
last March 13, first December 8

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 27May 18May 11May 5May 1Apr 26Apr 22Apr 18Apr 11
32°FMay 10Apr 27Apr 20Apr 16Apr 12Apr 8Apr 3Mar 28Mar 13
28°FApr 14Apr 5Mar 30Mar 21Mar 13Mar 6Feb 28Feb 18Jan 31
24°FMar 19Mar 5Feb 27Feb 18Feb 8Jan 29Jan 17Jan 6Dec 22
20°FFeb 26Feb 15Jan 31Jan 20Jan 9Jan 3Dec 30Dec 21Dec 11
16°F–––––––––

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 9Oct 18Oct 24Oct 30Nov 3Nov 9Nov 13Nov 17Nov 22
32°FOct 29Nov 5Nov 12Nov 16Nov 21Nov 24Nov 28Dec 3Dec 9
28°FNov 18Nov 24Nov 30Dec 4Dec 8Dec 12Dec 17Dec 26Jan 6
24°FDec 1Dec 10Dec 20Dec 28Jan 1Jan 9Jan 20Feb 1Feb 18
20°FDec 9Dec 16Dec 23Dec 30Jan 3Jan 11Jan 23Feb 3Feb 20
16°F–––––––––

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°F214203196189183176170160148
32°F255242233227221215207199182
28°F316298287276269259250241229
24°F365365353337326313305292278
20°F365365365365365365362346323
16°F365365365365365365365365365

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
99% of years
24°F or colder
80% of years
20°F or colder
31% of years
16°F or colder
7% 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
3,698
Cooling degree days, base 65°F
1,251
Growing degree days, base 40°F
6,806
Growing degree days, base 45°F
5,258
Growing degree days, base 50°F
3,939
Growing degree days, base 55°F
2,855
Growing degree days, base 60°F
1,969

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January640027
February549035
March520072
April3816140
May21046316
June58173567
July3368831
August2360823
September33228645
October17066375
November454295
December679013

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 16.7 km from Coloma. 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 USC00043384 (Georgetown RS). Public domain.