Keiser climate

Keiser Frost Dates and Growing Season

NOAA 1991-2020 normals for Keiser, 1.4 km from Keiser, elevation 232 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Keiser. 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 March 23 and the first fall freeze around November 6, a growing season of about 229 days.

Median at 36°F
last April 3, first October 28
Median at 32°F
last March 23, first November 6
Median at 28°F
last March 8, first November 22

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°FApr 19Apr 13Apr 9Apr 6Apr 3Mar 31Mar 28Mar 23Mar 17
32°FApr 8Apr 3Mar 30Mar 26Mar 23Mar 19Mar 15Mar 10Mar 4
28°FMar 29Mar 21Mar 16Mar 13Mar 8Mar 5Mar 2Feb 27Feb 20
24°FMar 17Mar 12Mar 7Mar 3Feb 28Feb 24Feb 19Feb 12Feb 5
20°FMar 10Mar 2Feb 27Feb 22Feb 16Feb 9Feb 3Jan 29Jan 18
16°FMar 2Feb 24Feb 15Feb 6Feb 1Jan 28Jan 22Jan 15Jan 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 12Oct 18Oct 22Oct 25Oct 28Oct 31Nov 2Nov 5Nov 10
32°FOct 23Oct 29Nov 1Nov 3Nov 6Nov 9Nov 15Nov 19Nov 27
28°FNov 2Nov 7Nov 12Nov 17Nov 22Nov 27Dec 1Dec 6Dec 14
24°FNov 13Nov 21Nov 27Dec 2Dec 7Dec 13Dec 20Dec 26Jan 3
20°FDec 1Dec 9Dec 17Dec 24Dec 29Jan 2Jan 8Jan 16Jan 26
16°FDec 12Dec 22Dec 29Jan 3Jan 7Jan 12Jan 17Jan 26Feb 4

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°F229220215212208203199194187
32°F254245239234229224219215206
28°F284275267262256251245239227
24°F315304296290284277270264254
20°F344333324316309303296289277
16°F365363354345337331322311300

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
97% of years
16°F or colder
82% 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
3,357
Cooling degree days, base 65°F
2,133
Growing degree days, base 40°F
8,239
Growing degree days, base 45°F
6,730
Growing degree days, base 50°F
5,363
Growing degree days, base 55°F
4,143
Growing degree days, base 60°F
3,066

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January806023
February616143
March43411148
April16668368
May30230665
June1442891
July0530995
August0479944
September15279714
October15382404
November4349131
December701137

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 1.4 km from Keiser. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

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Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00033821 (Keiser). Public domain.