Parks climate

Parks Frost Dates and Growing Season

NOAA 1991-2020 normals for Bellemont WFO, 12 km from Parks, elevation 7152 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Bellemont WFO. 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 21 and the first fall freeze around September 17, a growing season of about 85 days.

Median at 32°F
last June 21, first September 17
Median at 28°F
last June 9, first September 27

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°FJul 4Jun 30Jun 27Jun 23Jun 21Jun 18Jun 15Jun 13Jun 9
28°FJun 22Jun 18Jun 15Jun 12Jun 9Jun 7Jun 5Jun 2May 28
24°FJun 11Jun 6Jun 3Jun 1May 28May 22May 18May 14May 7
20°FMay 30May 19May 14May 9May 5May 2Apr 29Apr 25Apr 19
16°FMay 7May 1Apr 26Apr 20Apr 16Apr 13Apr 8Apr 3Mar 26

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°FSep 3Sep 7Sep 11Sep 14Sep 17Sep 20Sep 22Sep 25Sep 29
28°FSep 15Sep 19Sep 23Sep 25Sep 27Sep 30Oct 2Oct 5Oct 9
24°FSep 25Sep 28Oct 1Oct 3Oct 5Oct 8Oct 11Oct 14Oct 20
20°FOct 2Oct 5Oct 10Oct 13Oct 17Oct 21Oct 24Oct 28Nov 3
16°FOct 12Oct 19Oct 23Oct 26Oct 30Nov 2Nov 5Nov 10Nov 15

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°F817671676459554941
32°F1039793898582777365
28°F1261191141111071041019791
24°F157148142136132127123118112
20°F187181174169164159153148137
16°F222214207201196190185177169

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
7,548
Cooling degree days, base 65°F
46
Growing degree days, base 40°F
3,053
Growing degree days, base 45°F
2,088
Growing degree days, base 50°F
1,318
Growing degree days, base 55°F
706
Growing degree days, base 60°F
268

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,15900
February96600
March88700
April71003
May502060
June2324229
July5928434
August8913389
September2810184
October611020
November89000
December1,16200

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 12 km from Parks. 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 USC00020678 (Bellemont WFO). Public domain.