Potter County climate

Potter County Frost Dates and Growing Season

NOAA 1991-2020 normals for Amarillo, 25.1 km from Potter County, elevation 3587 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Amarillo. 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 13 and the first fall freeze around October 27, a growing season of about 195 days.

Median at 36°F
last April 25, first October 18
Median at 32°F
last April 13, first October 27
Median at 28°F
last April 2, first November 5

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 7May 3Apr 30Apr 27Apr 25Apr 22Apr 19Apr 14Apr 9
32°FApr 29Apr 25Apr 20Apr 17Apr 13Apr 9Apr 6Apr 2Mar 29
28°FApr 19Apr 13Apr 8Apr 5Apr 2Mar 30Mar 25Mar 20Mar 13
24°FApr 7Apr 2Mar 29Mar 23Mar 19Mar 15Mar 10Mar 7Mar 2
20°FMar 30Mar 20Mar 13Mar 9Mar 6Mar 2Feb 27Feb 22Feb 16
16°FMar 11Mar 6Mar 1Feb 25Feb 20Feb 16Feb 11Feb 4Jan 23

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 4Oct 9Oct 13Oct 15Oct 18Oct 20Oct 23Oct 25Oct 29
32°FOct 14Oct 18Oct 22Oct 25Oct 27Oct 30Nov 1Nov 4Nov 8
28°FOct 22Oct 28Oct 31Nov 2Nov 5Nov 7Nov 10Nov 14Nov 18
24°FOct 30Nov 4Nov 7Nov 10Nov 13Nov 16Nov 19Nov 22Nov 27
20°FNov 5Nov 12Nov 16Nov 19Nov 22Nov 26Nov 29Dec 4Dec 10
16°FNov 15Nov 20Nov 25Nov 30Dec 4Dec 9Dec 13Dec 18Dec 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°F195189183179175172168164157
32°F217209204200195191187182176
28°F236229224220216212207202194
24°F261253247241236232226220212
20°F289279272267261255250244233
16°F322309301294287281275267258

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
3,872
Cooling degree days, base 65°F
1,609
Growing degree days, base 40°F
7,313
Growing degree days, base 45°F
5,857
Growing degree days, base 50°F
4,554
Growing degree days, base 55°F
3,415
Growing degree days, base 60°F
2,439

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January820012
February650131
March4765118
April25124258
May78132522
June3335781
July0454919
August1408873
September31208628
October21939313
November530285
December812014

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 25.1 km from Potter 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 USW00023047 (Amarillo). Public domain.