Sterling climate

Sterling Frost Dates and Growing Season

NOAA 1991-2020 normals for Acme Mesonet, 15 km from Sterling, elevation 1302 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Acme Mesonet. 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 4 and the first fall freeze around October 31, a growing season of about 210 days.

Median at 36°F
last April 17, first October 23
Median at 32°F
last April 4, first October 31
Median at 28°F
last March 21, first November 8

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 2Apr 28Apr 23Apr 20Apr 17Apr 14Apr 10Apr 5Mar 31
32°FApr 23Apr 17Apr 12Apr 8Apr 4Apr 1Mar 29Mar 23Mar 16
28°FApr 10Apr 3Mar 31Mar 26Mar 21Mar 18Mar 13Mar 9Mar 1
24°FMar 30Mar 22Mar 17Mar 13Mar 9Mar 4Mar 1Feb 24Feb 17
20°FMar 17Mar 10Mar 5Mar 1Feb 25Feb 20Feb 13Feb 6Jan 27
16°FMar 6Feb 28Feb 22Feb 13Feb 7Feb 1Jan 26Jan 17Jan 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 7Oct 14Oct 17Oct 20Oct 23Oct 25Oct 28Oct 31Nov 4
32°FOct 16Oct 21Oct 25Oct 28Oct 31Nov 3Nov 6Nov 9Nov 14
28°FOct 22Oct 30Nov 2Nov 5Nov 8Nov 11Nov 14Nov 19Nov 27
24°FNov 1Nov 6Nov 10Nov 13Nov 18Nov 22Nov 26Dec 2Dec 9
20°FNov 10Nov 17Nov 23Nov 27Dec 1Dec 5Dec 10Dec 17Dec 26
16°FNov 22Nov 29Dec 4Dec 10Dec 17Dec 23Dec 29Jan 4Jan 16

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°F211204198193189184179175169
32°F233226220215210205199193186
28°F259250243238232227222215206
24°F284274267261256250244237227
20°F314302294287280274266259247
16°F349336328320313305296288276

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
97% 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
3,424
Cooling degree days, base 65°F
2,038
Growing degree days, base 40°F
8,104
Growing degree days, base 45°F
6,592
Growing degree days, base 50°F
5,224
Growing degree days, base 55°F
4,009
Growing degree days, base 60°F
2,948

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January783022
February599258
March41213166
April19446324
May51173588
June0389838
July05421,007
August0521985
September21270699
October17276386
November4466125
December747026

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 15 km from Sterling. 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 USC00340010 (Acme Mesonet). Public domain.