Leary climate

Leary Frost Dates and Growing Season

NOAA 1991-2020 normals for Newton 8 W, 19.7 km from Leary, elevation 176 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Newton 8 W. 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 11 and the first fall freeze around November 13, a growing season of about 245 days.

Median at 36°F
last March 27, first November 2
Median at 32°F
last March 11, first November 13
Median at 28°F
last February 27, first November 26

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 14Apr 8Apr 4Mar 31Mar 27Mar 23Mar 18Mar 12Mar 2
32°FApr 1Mar 25Mar 19Mar 16Mar 11Mar 7Mar 2Feb 26Feb 19
28°FMar 18Mar 12Mar 6Mar 2Feb 27Feb 23Feb 18Feb 12Feb 4
24°FMar 8Feb 28Feb 22Feb 17Feb 12Feb 7Feb 2Jan 27Jan 11
20°FFeb 26Feb 15Feb 9Feb 3Jan 30Jan 24Jan 17Jan 7Dec 28
16°FFeb 12Feb 6Feb 1Jan 28Jan 22Jan 14Jan 8Jan 2Dec 24

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 20Oct 25Oct 28Oct 31Nov 2Nov 5Nov 8Nov 12Nov 17
32°FOct 29Nov 2Nov 6Nov 9Nov 13Nov 15Nov 19Nov 24Dec 2
28°FNov 8Nov 13Nov 17Nov 21Nov 26Dec 1Dec 6Dec 14Dec 28
24°FNov 18Nov 26Dec 1Dec 6Dec 15Dec 27Jan 2Jan 10Jan 27
20°FDec 1Dec 8Dec 20Dec 30Jan 3Jan 10Jan 18Jan 30Feb 7
16°FDec 12Dec 27Jan 1Jan 7Jan 13Jan 21Jan 28Feb 1Feb 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°F245236230224219214209204196
32°F271262255249245240235228219
28°F307294286279272267261254243
24°F344333324315308301293282269
20°F365365360347339333326315305
16°F365365365365365365361345331

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
96% of years
20°F or colder
72% of years
16°F or colder
31% 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
1,910
Cooling degree days, base 65°F
2,255
Growing degree days, base 40°F
9,517
Growing degree days, base 45°F
7,791
Growing degree days, base 50°F
6,180
Growing degree days, base 55°F
4,707
Growing degree days, base 60°F
3,389

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January4976115
February3558143
March20533310
April7680457
May9257713
June0411861
July0498962
August0474939
September2331778
October65123524
November26625237
December43410141

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 19.7 km from Leary. 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 USW00063828 (Newton 8 W). Public domain.