Moravia climate

Moravia Frost Dates and Growing Season

NOAA 1991-2020 normals for Rathbun Dam, 9.8 km from Moravia, elevation 965 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Rathbun Dam. 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 18 and the first fall freeze around October 23, a growing season of about 187 days.

Median at 36°F
last April 29, first October 14
Median at 32°F
last April 18, first October 23
Median at 28°F
last April 7, first October 31

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 11May 6May 4May 1Apr 29Apr 26Apr 23Apr 19Apr 14
32°FMay 2Apr 28Apr 24Apr 21Apr 18Apr 15Apr 11Apr 8Apr 4
28°FApr 21Apr 16Apr 12Apr 10Apr 7Apr 4Apr 1Mar 29Mar 22
24°FApr 13Apr 7Apr 3Apr 1Mar 30Mar 26Mar 22Mar 16Mar 11
20°FApr 3Mar 30Mar 26Mar 22Mar 18Mar 15Mar 12Mar 8Mar 4
16°FMar 28Mar 21Mar 17Mar 13Mar 11Mar 8Mar 5Mar 3Feb 28

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 29Oct 3Oct 7Oct 11Oct 14Oct 16Oct 18Oct 22Oct 24
32°FOct 10Oct 15Oct 18Oct 20Oct 23Oct 24Oct 27Oct 29Nov 1
28°FOct 20Oct 24Oct 26Oct 28Oct 31Nov 1Nov 3Nov 5Nov 9
24°FOct 28Nov 1Nov 2Nov 4Nov 6Nov 9Nov 12Nov 15Nov 20
20°FNov 3Nov 7Nov 9Nov 12Nov 15Nov 18Nov 21Nov 25Dec 1
16°FNov 8Nov 13Nov 17Nov 20Nov 23Nov 26Dec 1Dec 3Dec 9

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°F185178174170166163159155148
32°F204198194190187183179175169
28°F226218213210206203199194187
24°F244236231227223219215211205
20°F262254249244240236231227219
16°F277271266261256252249244237

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
6,263
Cooling degree days, base 65°F
976
Growing degree days, base 40°F
5,531
Growing degree days, base 45°F
4,375
Growing degree days, base 50°F
3,337
Growing degree days, base 55°F
2,423
Growing degree days, base 60°F
1,630

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,33300
February1,08903
March815136
April4496122
May17158362
June19203634
July2321784
August6270728
September95101459
October37815178
November764029
December1,14202

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 9.8 km from Moravia. 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 USC00136910 (Rathbun Dam). Public domain.