Sheldon climate

Sheldon Frost Dates and Growing Season

NOAA 1991-2020 normals for Lamar 7N, 6.7 km from Sheldon, elevation 963 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Lamar 7N. 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 9 and the first fall freeze around October 27, a growing season of about 199 days.

Median at 36°F
last April 22, first October 18
Median at 32°F
last April 9, first October 27
Median at 28°F
last March 31, 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 6May 2Apr 29Apr 25Apr 22Apr 18Apr 14Apr 10Apr 5
32°FApr 28Apr 22Apr 17Apr 13Apr 9Apr 6Apr 3Mar 31Mar 26
28°FApr 14Apr 9Apr 5Apr 2Mar 31Mar 28Mar 23Mar 19Mar 13
24°FApr 4Mar 31Mar 26Mar 22Mar 18Mar 14Mar 10Mar 6Feb 28
20°FMar 24Mar 18Mar 14Mar 11Mar 6Mar 3Feb 28Feb 24Feb 17
16°FMar 15Mar 8Mar 5Mar 2Feb 26Feb 22Feb 17Feb 12Feb 4

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 2Oct 8Oct 12Oct 15Oct 18Oct 20Oct 23Oct 26Oct 30
32°FOct 13Oct 18Oct 22Oct 25Oct 27Oct 30Nov 1Nov 4Nov 10
28°FOct 22Oct 28Oct 31Nov 2Nov 5Nov 8Nov 11Nov 16Nov 23
24°FOct 31Nov 4Nov 8Nov 12Nov 15Nov 20Nov 25Nov 29Dec 4
20°FNov 6Nov 12Nov 18Nov 22Nov 26Nov 30Dec 3Dec 8Dec 15
16°FNov 15Nov 24Nov 28Dec 2Dec 6Dec 11Dec 16Dec 21Dec 29

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°F198191186182177174169164155
32°F221213208203199194189183175
28°F243235229224220216211205196
24°F267259253247242237232226218
20°F290281275269264259255247237
16°F314303297290284279274267259

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
4,620
Cooling degree days, base 65°F
1,341
Growing degree days, base 40°F
6,627
Growing degree days, base 45°F
5,284
Growing degree days, base 50°F
4,084
Growing degree days, base 55°F
3,028
Growing degree days, base 60°F
2,111

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,00906
February791016
March602377
April30918213
May10790451
June9262703
July1400865
August2367831
September50166567
October26232270
November580373
December899012

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 6.7 km from Sheldon. 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 USC00234705 (Lamar 7N). Public domain.