Ada climate

Ada Frost Dates and Growing Season

NOAA 1991-2020 normals for Lima Allen CO AP, 18.5 km from Ada, elevation 975 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Lima Allen CO AP. 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 22 and the first fall freeze around October 22, a growing season of about 181 days.

Median at 36°F
last May 2, first October 9
Median at 32°F
last April 22, first October 22
Median at 28°F
last April 11, first November 2

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

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°FSep 24Sep 30Oct 4Oct 6Oct 9Oct 13Oct 16Oct 19Oct 24
32°FOct 7Oct 12Oct 16Oct 20Oct 22Oct 25Oct 28Oct 31Nov 4
28°FOct 20Oct 25Oct 28Oct 31Nov 2Nov 4Nov 7Nov 11Nov 17
24°FNov 1Nov 4Nov 7Nov 10Nov 13Nov 17Nov 20Nov 25Dec 1
20°FNov 8Nov 13Nov 18Nov 21Nov 25Nov 30Dec 2Dec 7Dec 15
16°FNov 18Nov 25Nov 29Dec 2Dec 6Dec 11Dec 16Dec 21Dec 26

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°F178172167163159154150145138
32°F202196190186181178174169161
28°F225218213209206201197192185
24°F252244238233229225220215208
20°F279268263257252248243237229
16°F300290283278273267262255247

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
5,769
Cooling degree days, base 65°F
847
Growing degree days, base 40°F
5,494
Growing degree days, base 45°F
4,292
Growing degree days, base 50°F
3,226
Growing degree days, base 55°F
2,295
Growing degree days, base 60°F
1,501

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,17503
February98405
March805235
April4358127
May16965370
June25191616
July3263725
August9210666
September9091454
October36216182
November693037
December1,02006

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 18.5 km from Ada. 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 USW00004850 (Lima Allen CO AP). Public domain.