Reagan County climate

Reagan County Frost Dates and Growing Season

NOAA 1991-2020 normals for Big Lake 2, 19.3 km from Reagan County, elevation 2734 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Big Lake 2. 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 20 and the first fall freeze around November 14, a growing season of about 238 days.

Median at 36°F
last April 5, first November 4
Median at 32°F
last March 20, first November 14
Median at 28°F
last March 4, first November 25

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 24Apr 18Apr 13Apr 8Apr 5Apr 2Mar 31Mar 24Mar 17
32°FApr 10Apr 4Apr 1Mar 26Mar 20Mar 16Mar 11Mar 6Feb 28
28°FMar 26Mar 17Mar 11Mar 7Mar 4Feb 28Feb 24Feb 19Feb 10
24°FMar 12Mar 5Mar 1Feb 24Feb 19Feb 13Feb 5Jan 30Jan 18
20°FMar 2Feb 22Feb 13Feb 5Jan 31Jan 23Jan 14Jan 4Dec 20
16°FFeb 23Feb 8Feb 2Jan 23Jan 14Jan 5Dec 31Dec 22Dec 9

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 19Oct 25Oct 30Nov 1Nov 4Nov 7Nov 9Nov 13Nov 20
32°FOct 30Nov 4Nov 8Nov 10Nov 14Nov 17Nov 21Nov 26Dec 2
28°FNov 7Nov 13Nov 17Nov 21Nov 25Nov 29Dec 3Dec 8Dec 17
24°FNov 17Nov 23Nov 27Dec 2Dec 8Dec 15Dec 21Dec 30Jan 9
20°FNov 26Dec 5Dec 13Dec 22Dec 30Jan 4Jan 12Jan 23Feb 4
16°FDec 1Dec 12Dec 21Dec 29Jan 3Jan 11Jan 22Feb 1Feb 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°F239228222217212207201194187
32°F264256250244238232226218211
28°F294284278271265259253246236
24°F334320309302295289281272261
20°F365362350340332326317306295
16°F365365365365365362350336325

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
99% of years
20°F or colder
82% of years
16°F or colder
42% 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
2,173
Cooling degree days, base 65°F
2,503
Growing degree days, base 40°F
9,562
Growing degree days, base 45°F
7,869
Growing degree days, base 50°F
6,291
Growing degree days, base 55°F
4,865
Growing degree days, base 60°F
3,602

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January562164
February3954123
March22936307
April72120502
May13297749
June0470919
July05491,014
August05441,009
September9333775
October75134530
November29616217
December522183

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 19.3 km from Reagan 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 USC00410779 (Big Lake 2). Public domain.