Veblen climate

Veblen Frost Dates and Growing Season

NOAA 1991-2020 normals for Roy Lake, 20.6 km from Veblen, elevation 1810 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Roy Lake. 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 2 and the first fall freeze around October 9, a growing season of about 160 days.

Median at 36°F
last May 11, first October 1
Median at 32°F
last May 2, first October 9
Median at 28°F
last April 24, first October 20

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 24May 19May 16May 13May 11May 8May 6May 3Apr 30
32°FMay 15May 10May 8May 5May 2Apr 30Apr 28Apr 24Apr 19
28°FMay 6May 2Apr 30Apr 27Apr 24Apr 21Apr 18Apr 14Apr 8
24°FApr 29Apr 23Apr 20Apr 17Apr 15Apr 11Apr 8Apr 6Apr 2
20°FApr 20Apr 16Apr 12Apr 9Apr 7Apr 5Apr 3Mar 31Mar 25
16°FApr 14Apr 9Apr 6Apr 3Apr 1Mar 31Mar 27Mar 22Mar 16

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 20Sep 24Sep 27Sep 29Oct 1Oct 3Oct 6Oct 10Oct 14
32°FSep 27Sep 30Oct 3Oct 6Oct 9Oct 12Oct 15Oct 19Oct 22
28°FOct 5Oct 10Oct 13Oct 16Oct 20Oct 22Oct 25Oct 29Nov 1
24°FOct 14Oct 19Oct 23Oct 27Oct 29Nov 1Nov 3Nov 6Nov 11
20°FOct 23Oct 29Nov 1Nov 3Nov 6Nov 8Nov 11Nov 14Nov 20
16°FNov 1Nov 4Nov 7Nov 10Nov 13Nov 15Nov 18Nov 21Nov 26

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°F160153149145141139135131125
32°F177171166163160156152149143
28°F197191186181178174169165159
24°F215209204200196192188183175
20°F230223219215212209204200193
16°F245238233229225221217213206

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
8,417
Cooling degree days, base 65°F
619
Growing degree days, base 40°F
4,394
Growing degree days, base 45°F
3,413
Growing degree days, base 50°F
2,541
Growing degree days, base 55°F
1,778
Growing degree days, base 60°F
1,136

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,64000
February1,38900
March1,15602
April677037
May29124239
June59120513
July12229682
August19185631
September16758353
October560483
November1,00402
December1,44500

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 20.6 km from Veblen. 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 USC00397326 (Roy Lake). Public domain.