Muddy climate

Muddy Frost Dates and Growing Season

NOAA 1991-2020 normals for Busby, 18 km from Muddy, elevation 3430 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Busby. 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 23 and the first fall freeze around September 15, a growing season of about 113 days.

Median at 36°F
last June 8, first September 4
Median at 32°F
last May 23, first September 15
Median at 28°F
last May 11, 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°FJul 2Jun 22Jun 16Jun 13Jun 8Jun 5Jun 2May 29May 24
32°FJun 7Jun 1May 29May 26May 23May 21May 18May 15May 12
28°FMay 24May 19May 16May 13May 11May 9May 6May 3Apr 30
24°FMay 11May 6May 2Apr 30Apr 29Apr 26Apr 23Apr 20Apr 14
20°FMay 2Apr 28Apr 24Apr 20Apr 17Apr 14Apr 10Apr 5Apr 1
16°FApr 24Apr 17Apr 12Apr 8Apr 4Apr 1Mar 29Mar 23Mar 15

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°FAug 20Aug 26Aug 30Sep 1Sep 4Sep 6Sep 9Sep 13Sep 18
32°FSep 1Sep 5Sep 9Sep 12Sep 15Sep 18Sep 21Sep 25Oct 1
28°FSep 11Sep 17Sep 21Sep 24Sep 27Oct 1Oct 3Oct 6Oct 11
24°FSep 23Sep 28Oct 1Oct 4Oct 6Oct 9Oct 13Oct 16Oct 21
20°FOct 1Oct 6Oct 10Oct 14Oct 17Oct 20Oct 23Oct 26Oct 31
16°FOct 9Oct 15Oct 19Oct 23Oct 26Oct 29Nov 1Nov 4Nov 8

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°F10710095918682776960
32°F1311251211171131081059993
28°F155148144140136132128124117
24°F178172167162158155151146139
20°F202194190185180175171166157
16°F224217211206201197191186177

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
7,682
Cooling degree days, base 65°F
443
Growing degree days, base 40°F
4,040
Growing degree days, base 45°F
3,019
Growing degree days, base 50°F
2,154
Growing degree days, base 55°F
1,442
Growing degree days, base 60°F
869

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,35500
February1,13900
March91905
April627032
May3635159
June11950384
July22196638
August34160592
September21131289
October608153
November97203
December1,31300

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 18 km from Muddy. 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 USC00241297 (Busby). Public domain.