Wall climate

Wall Frost Dates and Growing Season

NOAA 1991-2020 normals for Wasta, 18.6 km from Wall, elevation 2328 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Wasta. 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 May 10 and the first fall freeze around October 1, a growing season of about 141 days.

Median at 36°F
last May 20, first September 22
Median at 32°F
last May 10, first October 1
Median at 28°F
last April 30, first October 9

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°FJun 2May 29May 26May 23May 20May 17May 15May 12May 8
32°FMay 25May 19May 16May 13May 10May 8May 6May 3Apr 30
28°FMay 13May 8May 5May 3Apr 30Apr 27Apr 24Apr 21Apr 16
24°FMay 2Apr 28Apr 25Apr 22Apr 18Apr 15Apr 12Apr 8Apr 4
20°FApr 23Apr 18Apr 14Apr 11Apr 8Apr 5Apr 2Mar 31Mar 25
16°FApr 14Apr 8Apr 4Apr 1Mar 30Mar 27Mar 22Mar 18Mar 11

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 7Sep 12Sep 16Sep 19Sep 22Sep 24Sep 27Oct 1Oct 4
32°FSep 14Sep 21Sep 25Sep 28Oct 1Oct 4Oct 6Oct 9Oct 13
28°FSep 26Oct 1Oct 4Oct 6Oct 9Oct 12Oct 15Oct 17Oct 21
24°FOct 4Oct 8Oct 12Oct 15Oct 18Oct 20Oct 23Oct 26Oct 31
20°FOct 11Oct 18Oct 20Oct 23Oct 25Oct 28Oct 31Nov 4Nov 8
16°FOct 19Oct 24Oct 27Oct 30Nov 1Nov 5Nov 8Nov 13Nov 18

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°F140134130126123119115111105
32°F159153149145141137133128122
28°F180173168164161157153147141
24°F200193189185181177172167160
20°F219211207202199194190186179
16°F238231225220216211207202193

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
7,065
Cooling degree days, base 65°F
819
Growing degree days, base 40°F
4,874
Growing degree days, base 45°F
3,793
Growing degree days, base 50°F
2,854
Growing degree days, base 55°F
2,052
Growing degree days, base 60°F
1,372

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,32500
February1,09702
March893018
April562272
May28323245
June63127516
July8303761
August16269718
September14388409
October5226104
November900010
December1,25400

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 18.6 km from Wall. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00398911 (Wasta). Public domain.