Waterproof climate

Waterproof Frost Dates and Growing Season

NOAA 1991-2020 normals for St Joseph 3 N, 21.4 km from Waterproof, elevation 78 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for St Joseph 3 N. 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 March 13 and the first fall freeze around November 10, a growing season of about 242 days.

Median at 36°F
last March 29, first November 1
Median at 32°F
last March 13, first November 10
Median at 28°F
last February 27, first November 22

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°FApr 16Apr 8Apr 5Apr 1Mar 29Mar 25Mar 19Mar 13Mar 6
32°FApr 4Mar 27Mar 21Mar 16Mar 13Mar 9Mar 4Feb 28Feb 20
28°FMar 19Mar 12Mar 8Mar 3Feb 27Feb 23Feb 18Feb 8Jan 30
24°FMar 6Feb 27Feb 20Feb 14Feb 7Jan 31Jan 26Jan 19Jan 5
20°FFeb 22Feb 10Feb 3Jan 29Jan 22Jan 17Jan 11Jan 1Dec 22
16°FFeb 7Feb 1Jan 27Jan 21Jan 16Jan 11Jan 7Jan 1Dec 17

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 18Oct 22Oct 26Oct 30Nov 1Nov 3Nov 6Nov 10Nov 16
32°FOct 27Nov 1Nov 4Nov 7Nov 10Nov 13Nov 18Nov 23Dec 1
28°FNov 3Nov 9Nov 13Nov 18Nov 22Nov 26Dec 1Dec 6Dec 19
24°FNov 12Nov 21Nov 29Dec 5Dec 10Dec 18Dec 27Jan 3Jan 14
20°FNov 28Dec 7Dec 16Dec 25Jan 1Jan 4Jan 11Jan 19Feb 1
16°FDec 11Dec 24Jan 1Jan 4Jan 9Jan 13Jan 18Jan 23Feb 1

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°F240234227222217212207202193
32°F270260254247242236231224216
28°F306292283277271265259250240
24°F346334326317309302294283271
20°F365365359351344336329320306
16°F365365365365365365364351339

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
97% of years
20°F or colder
71% of years
16°F or colder
30% 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
2,171
Cooling degree days, base 65°F
2,398
Growing degree days, base 40°F
9,445
Growing degree days, base 45°F
7,761
Growing degree days, base 50°F
6,196
Growing degree days, base 55°F
4,767
Growing degree days, base 60°F
3,496

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January559284
February4037125
March24327282
April9093457
May11272725
June0437886
July0525990
August0511976
September5359804
October85133517
November28424235
December4928115

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 21.4 km from Waterproof. 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 USC00168163 (St Joseph 3 N). Public domain.