Swisher County climate

Swisher County Frost Dates and Growing Season

NOAA 1991-2020 normals for Tulia, 3.1 km from Swisher County, elevation 3480 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Tulia. 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 18 and the first fall freeze around October 26, a growing season of about 189 days.

Median at 36°F
last April 28, first October 17
Median at 32°F
last April 18, first October 26
Median at 28°F
last April 7, first November 3

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 9May 5May 2Apr 30Apr 28Apr 26Apr 23Apr 19Apr 15
32°FMay 1Apr 27Apr 24Apr 21Apr 18Apr 15Apr 13Apr 10Apr 4
28°FApr 25Apr 19Apr 13Apr 10Apr 7Apr 4Apr 1Mar 27Mar 18
24°FApr 13Apr 7Apr 3Mar 31Mar 24Mar 19Mar 14Mar 10Mar 4
20°FMar 31Mar 23Mar 17Mar 12Mar 9Mar 6Mar 2Feb 28Feb 21
16°FMar 16Mar 9Mar 5Mar 1Feb 27Feb 22Feb 17Feb 10Jan 31

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 3Oct 8Oct 12Oct 15Oct 17Oct 19Oct 22Oct 25Oct 28
32°FOct 12Oct 17Oct 20Oct 23Oct 26Oct 28Oct 31Nov 3Nov 6
28°FOct 21Oct 26Oct 29Nov 1Nov 3Nov 5Nov 8Nov 11Nov 15
24°FOct 30Nov 3Nov 6Nov 9Nov 12Nov 15Nov 18Nov 22Nov 28
20°FNov 6Nov 11Nov 15Nov 19Nov 22Nov 25Nov 28Dec 2Dec 7
16°FNov 13Nov 21Nov 25Nov 28Dec 1Dec 5Dec 9Dec 14Dec 22

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°F188181177174171167163159153
32°F207202196193189185181177171
28°F231223216212208205200195188
24°F257248243238233228223216209
20°F281273265261257251247240233
16°F311300292285279274268262254

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
4,179
Cooling degree days, base 65°F
1,372
Growing degree days, base 40°F
6,848
Growing degree days, base 45°F
5,432
Growing degree days, base 50°F
4,176
Growing degree days, base 55°F
3,090
Growing degree days, base 60°F
2,158

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January87106
February692019
March531285
April29013218
May97108481
June4297742
July1403868
August1358821
September39165578
October24026285
November569165
December84509

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 3.1 km from Swisher County. 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 USC00419175 (Tulia). Public domain.