Moffat County climate

Moffat County Frost Dates and Growing Season

NOAA 1991-2020 normals for Maybell, 14.8 km from Moffat County, elevation 5944 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Maybell. 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 83 days.

Median at 32°F
last June 16, first September 9
Median at 28°F
last June 1, first September 19

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 1Jun 26Jun 22Jun 19Jun 16Jun 13Jun 9Jun 6May 31
28°FJun 18Jun 12Jun 7Jun 4Jun 1May 29May 25May 20May 15
24°FMay 31May 24May 20May 16May 14May 10May 7May 3Apr 30
20°FMay 14May 10May 6May 3Apr 30Apr 28Apr 24Apr 20Apr 14
16°FMay 4Apr 29Apr 25Apr 21Apr 17Apr 13Apr 8Apr 3Mar 29

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 26Sep 1Sep 3Sep 6Sep 9Sep 12Sep 14Sep 17Sep 22
28°FSep 5Sep 10Sep 13Sep 16Sep 19Sep 22Sep 24Sep 27Oct 1
24°FSep 16Sep 20Sep 23Sep 26Sep 29Oct 1Oct 4Oct 8Oct 13
20°FSep 25Sep 29Oct 2Oct 5Oct 9Oct 13Oct 16Oct 19Oct 23
16°FOct 4Oct 9Oct 13Oct 17Oct 19Oct 22Oct 25Oct 28Nov 1

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°F787166615752474235
32°F1039691878379746962
28°F1301231181131091051009587
24°F157150145141137133128122115
20°F183175169164160156151145139
16°F209199194188183179174167160

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
8,669
Cooling degree days, base 65°F
148
Growing degree days, base 40°F
3,253
Growing degree days, base 45°F
2,334
Growing degree days, base 50°F
1,564
Growing degree days, base 55°F
938
Growing degree days, base 60°F
456

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,51300
February1,20700
March99100
April717010
May455197
June18516288
July3479510
August6349451
September2933190
October698018
November1,06400
December1,45100

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 14.8 km from Moffat County. 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 USC00055446 (Maybell). Public domain.