Murdo climate

Murdo Frost Dates and Growing Season

NOAA 1991-2020 normals for Murdo, 0.4 km from Murdo, elevation 2316 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Murdo. 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 3 and the first fall freeze around October 9, a growing season of about 158 days.

Median at 36°F
last May 12, first October 1
Median at 32°F
last May 3, first October 9
Median at 28°F
last April 22, first October 18

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 24May 20May 17May 15May 12May 9May 7May 4May 1
32°FMay 16May 11May 8May 5May 3May 1Apr 28Apr 25Apr 19
28°FMay 6May 2Apr 29Apr 26Apr 22Apr 19Apr 16Apr 12Apr 8
24°FApr 28Apr 23Apr 19Apr 16Apr 13Apr 10Apr 7Apr 4Mar 31
20°FApr 19Apr 14Apr 10Apr 6Apr 4Apr 1Mar 29Mar 25Mar 18
16°FApr 10Apr 5Apr 2Mar 31Mar 28Mar 24Mar 19Mar 14Mar 8

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 18Sep 22Sep 25Sep 28Oct 1Oct 3Oct 6Oct 10Oct 14
32°FSep 25Sep 30Oct 3Oct 6Oct 9Oct 13Oct 15Oct 18Oct 22
28°FOct 3Oct 9Oct 13Oct 16Oct 18Oct 21Oct 24Oct 27Oct 31
24°FOct 14Oct 18Oct 21Oct 24Oct 26Oct 29Nov 1Nov 6Nov 10
20°FOct 19Oct 24Oct 28Nov 1Nov 3Nov 7Nov 10Nov 14Nov 19
16°FOct 27Nov 1Nov 5Nov 9Nov 12Nov 15Nov 18Nov 21Nov 26

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°F158152147144140136132128121
32°F177171165162158154150145138
28°F197190185180176172167162155
24°F217209204199195191187182175
20°F236229223218214209205200192
16°F254246239233230225220215207

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
7,208
Cooling degree days, base 65°F
846
Growing degree days, base 40°F
4,926
Growing degree days, base 45°F
3,858
Growing degree days, base 50°F
2,917
Growing degree days, base 55°F
2,101
Growing degree days, base 60°F
1,409

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,35900
February1,13803
March940020
April590271
May28627250
June60135527
July7306764
August15266716
September136102427
October5108121
November900018
December1,26601

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 0.4 km from Murdo. 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 USC00395891 (Murdo). Public domain.