Tyrone climate

Tyrone Frost Dates and Growing Season

NOAA 1991-2020 normals for Liberal, 16.4 km from Tyrone, elevation 2834 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Liberal. 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 20 and the first fall freeze around October 24, a growing season of about 186 days.

Median at 36°F
last April 30, first October 15
Median at 32°F
last April 20, first October 24
Median at 28°F
last April 9, 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 11May 7May 4May 1Apr 30Apr 28Apr 25Apr 20Apr 16
32°FMay 3Apr 30Apr 26Apr 23Apr 20Apr 17Apr 14Apr 10Apr 4
28°FApr 25Apr 19Apr 15Apr 12Apr 9Apr 5Apr 3Mar 31Mar 24
24°FApr 15Apr 9Apr 5Apr 2Mar 31Mar 27Mar 22Mar 16Mar 10
20°FApr 5Mar 31Mar 27Mar 21Mar 17Mar 13Mar 10Mar 5Mar 1
16°FMar 26Mar 18Mar 13Mar 10Mar 6Mar 3Feb 28Feb 23Feb 17

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 30Oct 5Oct 8Oct 12Oct 15Oct 18Oct 20Oct 22Oct 26
32°FOct 8Oct 16Oct 20Oct 22Oct 24Oct 26Oct 29Nov 1Nov 4
28°FOct 20Oct 24Oct 28Oct 30Nov 1Nov 3Nov 5Nov 9Nov 13
24°FOct 26Nov 1Nov 3Nov 5Nov 8Nov 11Nov 13Nov 17Nov 22
20°FNov 1Nov 6Nov 10Nov 13Nov 16Nov 19Nov 22Nov 26Dec 1
16°FNov 8Nov 15Nov 18Nov 22Nov 25Nov 28Dec 1Dec 5Dec 12

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°F187179175170167163160154147
32°F206199195190186183179174168
28°F225218213208205201197192186
24°F246238233228224220215210203
20°F267259253248243239233226219
16°F288279273268263259254248239

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
4,778
Cooling degree days, base 65°F
1,443
Growing degree days, base 40°F
6,599
Growing degree days, base 45°F
5,278
Growing degree days, base 50°F
4,109
Growing degree days, base 55°F
3,086
Growing degree days, base 60°F
2,200

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January97202
February795011
March607271
April33913193
May11895448
June9295736
July1440904
August3387849
September50183586
October28229258
November647146
December95803

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 16.4 km from Tyrone. 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 USC00144695 (Liberal). Public domain.