Hooper climate

Hooper Frost Dates and Growing Season

NOAA 1991-2020 normals for Ogden Hinkley AP, 9.9 km from Hooper, elevation 4470 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Ogden Hinkley AP. 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 April 22 and the first fall freeze around October 22, a growing season of about 180 days.

Median at 36°F
last May 8, first October 11
Median at 32°F
last April 22, first October 22
Median at 28°F
last April 3, first November 2

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 31May 23May 16May 12May 8May 4May 1Apr 28Apr 22
32°FMay 10May 3Apr 29Apr 26Apr 22Apr 19Apr 15Apr 11Apr 4
28°FApr 21Apr 16Apr 11Apr 7Apr 3Mar 31Mar 27Mar 20Mar 13
24°FApr 3Mar 29Mar 22Mar 16Mar 12Mar 8Mar 5Mar 2Feb 25
20°FMar 14Mar 9Mar 5Mar 2Feb 27Feb 24Feb 20Feb 16Feb 11
16°FMar 3Feb 27Feb 23Feb 19Feb 16Feb 12Feb 9Feb 4Jan 28

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 28Oct 2Oct 5Oct 7Oct 11Oct 14Oct 16Oct 21Oct 25
32°FOct 7Oct 12Oct 16Oct 19Oct 22Oct 25Oct 28Nov 1Nov 6
28°FOct 18Oct 23Oct 27Oct 30Nov 2Nov 5Nov 8Nov 12Nov 17
24°FOct 25Nov 1Nov 5Nov 8Nov 12Nov 15Nov 18Nov 22Nov 27
20°FNov 5Nov 10Nov 14Nov 18Nov 22Nov 25Nov 28Dec 2Dec 8
16°FNov 12Nov 19Nov 24Nov 28Dec 1Dec 5Dec 10Dec 15Dec 22

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°F176168163159155149144138129
32°F204195190185180177172167158
28°F238227220215210205198193185
24°F265257251246240235230224215
20°F288281276271267263258252243
16°F315307300295289284279274266

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
5,850
Cooling degree days, base 65°F
1,052
Growing degree days, base 40°F
5,421
Growing degree days, base 45°F
4,242
Growing degree days, base 50°F
3,226
Growing degree days, base 55°F
2,362
Growing degree days, base 60°F
1,648

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,13300
February88501
March685023
April479281
May23435286
June60162553
July1405869
August5339800
September92104468
October4155133
November765013
December1,09700

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 9.9 km from Hooper. 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 USW00024126 (Ogden Hinkley AP). Public domain.