Newell climate

Newell Frost Dates and Growing Season

NOAA 1991-2020 normals for Newell, 0.4 km from Newell, elevation 2860 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Newell. 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 8 and the first fall freeze around October 1, a growing season of about 144 days.

Median at 36°F
last May 18, first September 24
Median at 32°F
last May 8, first October 1
Median at 28°F
last April 30, first October 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°FJun 1May 27May 24May 21May 18May 16May 14May 10May 7
32°FMay 22May 16May 13May 10May 8May 6May 3May 1Apr 27
28°FMay 12May 7May 5May 2Apr 30Apr 27Apr 24Apr 20Apr 15
24°FMay 3Apr 28Apr 24Apr 20Apr 17Apr 14Apr 11Apr 6Apr 2
20°FApr 24Apr 18Apr 14Apr 11Apr 8Apr 4Apr 2Mar 30Mar 22
16°FApr 16Apr 10Apr 6Apr 3Apr 1Mar 29Mar 23Mar 17Mar 10

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 10Sep 15Sep 19Sep 22Sep 24Sep 27Sep 29Oct 2Oct 5
32°FSep 19Sep 23Sep 27Sep 30Oct 1Oct 4Oct 7Oct 10Oct 15
28°FSep 27Oct 1Oct 5Oct 8Oct 11Oct 14Oct 17Oct 20Oct 24
24°FOct 5Oct 11Oct 15Oct 18Oct 20Oct 23Oct 25Oct 28Nov 1
20°FOct 15Oct 19Oct 23Oct 25Oct 28Oct 30Nov 2Nov 5Nov 10
16°FOct 22Oct 27Oct 30Nov 1Nov 4Nov 7Nov 11Nov 15Nov 20

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°F143137134130126122118114107
32°F163156151147144140136131123
28°F182176172168164159155150143
24°F202196191187183179175169162
20°F222215209205201198193187180
16°F241234227222217213208203195

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
7,618
Cooling degree days, base 65°F
613
Growing degree days, base 40°F
4,381
Growing degree days, base 45°F
3,361
Growing degree days, base 50°F
2,476
Growing degree days, base 55°F
1,726
Growing degree days, base 60°F
1,102

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,37000
February1,15201
March974010
April637146
May34512190
June9085448
July13245697
August26209648
September17958346
October572383
November96007
December1,30000

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 0.4 km from Newell. 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 USC00396054 (Newell). Public domain.