Moenkopi climate

Moenkopi Frost Dates and Growing Season

NOAA 1991-2020 normals for Tuba City, 2.9 km from Moenkopi, elevation 4988 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Tuba City. 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 16 and the first fall freeze around October 28, a growing season of about 193 days.

Median at 36°F
last April 30, first October 17
Median at 32°F
last April 16, first October 28
Median at 28°F
last March 30, first November 7

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 22May 10May 5May 2Apr 30Apr 26Apr 23Apr 20Apr 15
32°FMay 4Apr 28Apr 24Apr 20Apr 16Apr 13Apr 10Apr 6Mar 31
28°FApr 21Apr 13Apr 7Apr 3Mar 30Mar 25Mar 19Mar 14Mar 8
24°FApr 6Mar 26Mar 17Mar 12Mar 8Mar 5Mar 2Feb 25Feb 18
20°FMar 11Mar 7Mar 2Feb 28Feb 22Feb 18Feb 13Feb 8Jan 31
16°FMar 1Feb 23Feb 16Feb 10Feb 5Jan 31Jan 24Jan 15Jan 5

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 1Oct 6Oct 11Oct 14Oct 17Oct 20Oct 24Oct 27Nov 1
32°FOct 13Oct 18Oct 22Oct 25Oct 28Oct 31Nov 3Nov 7Nov 12
28°FOct 22Oct 27Nov 1Nov 4Nov 7Nov 11Nov 14Nov 18Nov 22
24°FNov 2Nov 8Nov 13Nov 16Nov 19Nov 21Nov 24Nov 28Dec 3
20°FNov 14Nov 19Nov 23Nov 27Nov 29Dec 2Dec 5Dec 10Dec 15
16°FNov 25Nov 29Dec 3Dec 7Dec 10Dec 15Dec 19Dec 24Dec 31

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°F190184179174169164159152143
32°F217209203197193189183177166
28°F246238232226221215209203191
24°F277268262257252247240232220
20°F308299293286281274268261251
16°F342331324317310303295288279

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
99% 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
4,350
Cooling degree days, base 65°F
1,351
Growing degree days, base 40°F
6,591
Growing degree days, base 45°F
5,223
Growing degree days, base 50°F
4,031
Growing degree days, base 55°F
2,993
Growing degree days, base 60°F
2,100

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January91600
February68304
March518060
April3065184
May9878448
June10278718
July0440905
August1382846
September24157584
October24310252
November608030
December94400

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 2.9 km from Moenkopi. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

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Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00028792 (Tuba City). Public domain.