Apollo climate

Apollo Frost Dates and Growing Season

NOAA 1991-2020 normals for Salina 3 W, 8.1 km from Apollo, elevation 1109 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Salina 3 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 April 29 and the first fall freeze around October 20, a growing season of about 171 days.

Median at 36°F
last May 10, first October 7
Median at 32°F
last April 29, first October 20
Median at 28°F
last April 18, first November 1

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 28May 23May 18May 14May 10May 6May 3Apr 29Apr 24
32°FMay 17May 10May 5May 2Apr 29Apr 26Apr 22Apr 19Apr 14
28°FMay 4Apr 27Apr 24Apr 21Apr 18Apr 15Apr 11Apr 6Apr 1
24°FApr 19Apr 15Apr 11Apr 8Apr 5Apr 2Mar 31Mar 28Mar 22
20°FApr 9Apr 4Apr 1Mar 30Mar 27Mar 23Mar 19Mar 15Mar 10
16°FMar 30Mar 25Mar 20Mar 17Mar 14Mar 11Mar 8Mar 5Feb 28

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 25Sep 30Oct 1Oct 4Oct 7Oct 11Oct 14Oct 17Oct 22
32°FOct 5Oct 10Oct 14Oct 17Oct 20Oct 23Oct 27Oct 31Nov 4
28°FOct 16Oct 23Oct 27Oct 30Nov 1Nov 4Nov 7Nov 11Nov 16
24°FOct 31Nov 2Nov 6Nov 9Nov 12Nov 15Nov 18Nov 23Nov 30
20°FNov 7Nov 12Nov 16Nov 20Nov 24Nov 27Dec 1Dec 5Dec 12
16°FNov 17Nov 23Nov 28Dec 2Dec 6Dec 10Dec 16Dec 21Dec 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°F170163158153149145139135127
32°F193185180176171167163158151
28°F220211206202197193188183175
24°F243237231226222218213208202
20°F268259253248244239235228221
16°F292283276271266260255249240

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
5,895
Cooling degree days, base 65°F
667
Growing degree days, base 40°F
5,164
Growing degree days, base 45°F
3,975
Growing degree days, base 50°F
2,929
Growing degree days, base 55°F
2,026
Growing degree days, base 60°F
1,267

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,15005
February98005
March838128
April4675116
May21244314
June50128529
July8220677
August13183635
September10376427
October39610154
November690033
December98906

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 8.1 km from Apollo. 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 USC00367782 (Salina 3 W). Public domain.