Clay climate

Clay Frost Dates and Growing Season

NOAA 1991-2020 normals for Providence, 10 km from Clay, elevation 409 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Providence. 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 7 and the first fall freeze around October 28, a growing season of about 203 days.

Median at 36°F
last April 19, first October 18
Median at 32°F
last April 7, first October 28
Median at 28°F
last March 29, 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 4Apr 29Apr 26Apr 23Apr 19Apr 15Apr 12Apr 9Apr 4
32°FApr 24Apr 18Apr 13Apr 10Apr 7Apr 4Mar 31Mar 29Mar 23
28°FApr 14Apr 7Apr 3Mar 31Mar 29Mar 25Mar 21Mar 17Mar 10
24°FApr 3Mar 29Mar 24Mar 21Mar 17Mar 14Mar 9Mar 4Feb 26
20°FMar 23Mar 17Mar 14Mar 9Mar 6Mar 1Feb 26Feb 21Feb 13
16°FMar 15Mar 7Mar 3Feb 28Feb 23Feb 18Feb 13Feb 8Feb 2

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 5Oct 10Oct 13Oct 16Oct 18Oct 21Oct 23Oct 26Oct 29
32°FOct 15Oct 20Oct 23Oct 25Oct 28Oct 30Nov 1Nov 4Nov 8
28°FOct 24Oct 29Nov 1Nov 3Nov 5Nov 8Nov 11Nov 16Nov 23
24°FNov 3Nov 7Nov 10Nov 13Nov 16Nov 21Nov 26Dec 1Dec 6
20°FNov 10Nov 15Nov 21Nov 26Nov 30Dec 3Dec 8Dec 13Dec 21
16°FNov 19Nov 28Dec 1Dec 7Dec 12Dec 18Dec 23Dec 27Jan 3

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°F201195190186181178174169162
32°F223215210206203200195190183
28°F246238232226222217213208202
24°F271262255250246241235230221
20°F295286279273267262257250239
16°F320310303297291285277270261

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
4,280
Cooling degree days, base 65°F
1,583
Growing degree days, base 40°F
7,083
Growing degree days, base 45°F
5,704
Growing degree days, base 50°F
4,467
Growing degree days, base 55°F
3,369
Growing degree days, base 60°F
2,407

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January956013
February763021
March570591
April26432258
May70141537
June4325771
July0443908
August1393857
September33199617
October23542296
November551379
December832019

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 10 km from Clay. 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 USC00156595 (Providence). Public domain.