Loami climate

Loami Frost Dates and Growing Season

NOAA 1991-2020 normals for Virden, 20 km from Loami, elevation 675 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Virden. 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 29, a growing season of about 205 days.

Median at 36°F
last April 19, first October 19
Median at 32°F
last April 7, first October 29
Median at 28°F
last March 28, first November 7

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 5Apr 29Apr 25Apr 22Apr 19Apr 16Apr 13Apr 9Apr 4
32°FApr 21Apr 17Apr 13Apr 10Apr 7Apr 3Mar 31Mar 28Mar 22
28°FApr 12Apr 6Apr 2Mar 31Mar 28Mar 25Mar 22Mar 18Mar 11
24°FApr 1Mar 29Mar 25Mar 22Mar 19Mar 15Mar 10Mar 6Mar 1
20°FMar 25Mar 20Mar 16Mar 13Mar 9Mar 5Mar 2Feb 26Feb 19
16°FMar 19Mar 13Mar 9Mar 4Mar 1Feb 27Feb 22Feb 16Feb 7

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 4Oct 10Oct 13Oct 16Oct 19Oct 22Oct 24Oct 28Oct 31
32°FOct 16Oct 21Oct 25Oct 27Oct 29Oct 31Nov 3Nov 6Nov 11
28°FOct 27Oct 31Nov 2Nov 4Nov 7Nov 10Nov 13Nov 17Nov 22
24°FNov 3Nov 7Nov 11Nov 14Nov 17Nov 21Nov 25Nov 30Dec 5
20°FNov 8Nov 14Nov 19Nov 23Nov 28Dec 1Dec 5Dec 10Dec 17
16°FNov 19Nov 26Nov 30Dec 3Dec 7Dec 12Dec 17Dec 22Dec 27

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°F201195190185182177173167160
32°F225218212208205201197192185
28°F247240233229225220216211205
24°F269261255250246241236230223
20°F287279274268263259253248240
16°F308299292286281276271264256

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
5,002
Cooling degree days, base 65°F
1,321
Growing degree days, base 40°F
6,478
Growing degree days, base 45°F
5,196
Growing degree days, base 50°F
4,040
Growing degree days, base 55°F
3,007
Growing degree days, base 60°F
2,097

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,12803
February89208
March655363
April29526230
May93104477
June9280721
July0380845
August2327790
September45167572
October27134265
November639157
December97309

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 20 km from Loami. 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 USC00118860 (Virden). Public domain.