Carey climate

Carey Frost Dates and Growing Season

NOAA 1991-2020 normals for Picabo, 9.8 km from Carey, elevation 4839 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Picabo. 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 June 16 and the first fall freeze around September 9, a growing season of about 85 days.

Median at 32°F
last June 16, first September 9
Median at 28°F
last June 2, first September 23

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°F–––––––––
32°FJun 30Jun 25Jun 22Jun 19Jun 16Jun 14Jun 11Jun 8Jun 3
28°FJun 19Jun 14Jun 9Jun 5Jun 2May 27May 21May 15May 9
24°FJun 1May 20May 14May 9May 5May 3May 1Apr 27Apr 21
20°FMay 6May 2Apr 30Apr 27Apr 23Apr 20Apr 16Apr 11Apr 4
16°FApr 27Apr 19Apr 14Apr 10Apr 6Apr 1Mar 28Mar 19Mar 14

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°F–––––––––
32°FAug 25Aug 31Sep 3Sep 6Sep 9Sep 12Sep 16Sep 20Sep 24
28°FSep 5Sep 12Sep 16Sep 20Sep 23Sep 26Sep 29Oct 3Oct 7
24°FSep 19Sep 26Sep 30Oct 2Oct 5Oct 9Oct 12Oct 15Oct 20
20°FOct 3Oct 8Oct 14Oct 16Oct 19Oct 22Oct 24Oct 28Nov 1
16°FOct 16Oct 21Oct 24Oct 28Oct 30Nov 1Nov 4Nov 9Nov 14

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°F797166625854494337
32°F1079993888580767162
28°F1421331261201151091049788
24°F173166160156150145140132120
20°F201193188183179175171165157
16°F232224217212207202197191184

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
8,380
Cooling degree days, base 65°F
185
Growing degree days, base 40°F
3,266
Growing degree days, base 45°F
2,350
Growing degree days, base 50°F
1,592
Growing degree days, base 55°F
972
Growing degree days, base 60°F
498

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,41200
February1,16900
March99500
April714011
May4471103
June23512241
July4894512
August6370473
September2638219
October653033
November1,01100
December1,37000

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 9.8 km from Carey. 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 USC00107040 (Picabo). Public domain.