Oljato-Monument Valley climate

Oljato-Monument Valley Frost Dates and Growing Season

NOAA 1991-2020 normals for Monument Valley, 12.7 km from Oljato-Monument Valley, elevation 5501 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Monument Valley. 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 April 10 and the first fall freeze around November 1, a growing season of about 205 days.

Median at 36°F
last April 23, first October 21
Median at 32°F
last April 10, first November 1
Median at 28°F
last March 25, first November 12

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 9May 3Apr 30Apr 26Apr 23Apr 19Apr 16Apr 12Apr 6
32°FApr 30Apr 21Apr 17Apr 14Apr 10Apr 5Apr 1Mar 28Mar 20
28°FApr 14Apr 7Apr 3Mar 30Mar 25Mar 20Mar 15Mar 10Mar 4
24°FMar 31Mar 22Mar 16Mar 11Mar 7Mar 4Feb 28Feb 23Feb 16
20°FMar 11Mar 5Mar 1Feb 25Feb 20Feb 16Feb 10Feb 5Jan 25
16°FMar 3Feb 22Feb 14Feb 7Feb 2Jan 28Jan 19Jan 9Dec 31

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°FOct 5Oct 11Oct 15Oct 18Oct 21Oct 25Oct 28Nov 1Nov 5
32°FOct 17Oct 23Oct 27Oct 30Nov 1Nov 5Nov 8Nov 11Nov 16
28°FOct 27Nov 1Nov 6Nov 8Nov 12Nov 15Nov 18Nov 22Nov 26
24°FNov 6Nov 11Nov 16Nov 19Nov 22Nov 25Nov 28Dec 1Dec 6
20°FNov 17Nov 23Nov 27Dec 1Dec 3Dec 6Dec 9Dec 14Dec 19
16°FNov 26Dec 1Dec 5Dec 9Dec 14Dec 18Dec 23Dec 29Jan 11

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°F201195189185181177172167160
32°F229220214209205200194188181
28°F255247240234229224219214204
24°F282274268262257251246240230
20°F314303296290284278273267259
16°F350338330323315307300292282

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
96% 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
4,620
Cooling degree days, base 65°F
1,523
Growing degree days, base 40°F
6,672
Growing degree days, base 45°F
5,360
Growing degree days, base 50°F
4,194
Growing degree days, base 55°F
3,167
Growing degree days, base 60°F
2,276

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January98900
February75003
March546058
April3178182
May96104476
June7356799
July0477942
August1384848
September24179606
October24915255
November651024
December99201

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 12.7 km from Oljato-Monument Valley. 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 USC00025665 (Monument Valley). Public domain.