Wellton climate

Wellton Frost Dates and Growing Season

NOAA 1991-2020 normals for Tacna 3 Ne, 22 km from Wellton, elevation 324 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Tacna 3 Ne. 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 February 13 and the first fall freeze around December 1, a growing season of about 288 days.

Median at 36°F
last March 2, first November 19
Median at 32°F
last February 13, first December 1
Median at 28°F
last January 23, first December 11

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°FMar 19Mar 13Mar 8Mar 5Mar 2Feb 27Feb 22Feb 16Feb 7
32°FMar 5Feb 28Feb 23Feb 18Feb 13Feb 8Feb 2Jan 28Jan 19
28°FFeb 20Feb 9Feb 3Jan 30Jan 23Jan 16Jan 11Jan 5Dec 28
24°FFeb 3Jan 25Jan 17Jan 11Jan 6Jan 2Dec 29Dec 23Dec 14
20°FJan 27Jan 15Jan 10Jan 7Jan 5Jan 2Dec 30Dec 23Dec 14
16°F–––––––––

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°FNov 3Nov 10Nov 13Nov 17Nov 19Nov 22Nov 26Nov 30Dec 4
32°FNov 14Nov 20Nov 25Nov 28Dec 1Dec 3Dec 7Dec 11Dec 17
28°FNov 24Nov 30Dec 4Dec 7Dec 11Dec 15Dec 20Dec 25Jan 5
24°FDec 3Dec 9Dec 14Dec 18Dec 24Dec 31Jan 3Jan 10Jan 24
20°FDec 10Dec 16Dec 26Dec 31Jan 2Jan 5Jan 9Jan 13Jan 24
16°F–––––––––

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°F286277270265260255250244236
32°F318308301294288283276271261
28°F353345338331324318311303293
24°F365365365363356349342335325
20°F365365365365365365365365357
16°F365365365365365365365365365

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
97% of years
24°F or colder
65% of years
20°F or colder
18% of years
16°F or colder
2% 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
1,190
Cooling degree days, base 65°F
4,176
Growing degree days, base 40°F
12,112
Growing degree days, base 45°F
10,295
Growing degree days, base 50°F
8,521
Growing degree days, base 55°F
6,872
Growing degree days, base 60°F
5,422

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January3391147
February2056227
March8767445
April20189620
May1425888
June06721,122
July08931,358
August08961,361
September06801,129
October10306761
November14542350
December3830113

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 22 km from Wellton. 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 USC00028396 (Tacna 3 Ne). Public domain.