Towaoc climate

Towaoc Frost Dates and Growing Season

NOAA 1991-2020 normals for Cortez Montezuma CO AP, 14.2 km from Towaoc, elevation 5914 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Cortez Montezuma CO AP. 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 27 and the first fall freeze around September 28, a growing season of about 125 days.

Median at 36°F
last June 9, first September 20
Median at 32°F
last May 27, first September 28
Median at 28°F
last May 8, first October 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°FJun 24Jun 20Jun 16Jun 12Jun 9Jun 6Jun 3May 31May 26
32°FJun 11Jun 6Jun 2May 31May 27May 23May 20May 15May 9
28°FMay 31May 20May 15May 11May 8May 5May 2Apr 30Apr 25
24°FMay 10May 4May 1Apr 28Apr 25Apr 21Apr 18Apr 14Apr 9
20°FApr 29Apr 22Apr 18Apr 14Apr 10Apr 7Apr 3Mar 30Mar 21
16°FApr 10Apr 5Mar 31Mar 26Mar 20Mar 15Mar 11Mar 7Mar 2

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 8Sep 12Sep 14Sep 17Sep 20Sep 22Sep 24Sep 26Sep 30
32°FSep 17Sep 21Sep 23Sep 26Sep 28Oct 1Oct 3Oct 5Oct 10
28°FSep 26Sep 30Oct 3Oct 5Oct 7Oct 10Oct 13Oct 16Oct 21
24°FOct 4Oct 8Oct 11Oct 14Oct 17Oct 20Oct 23Oct 27Nov 1
20°FOct 13Oct 18Oct 21Oct 24Oct 28Oct 31Nov 3Nov 6Nov 12
16°FOct 22Oct 28Nov 1Nov 5Nov 8Nov 11Nov 15Nov 19Nov 23

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°F11911310810410097938882
32°F145139134129125120116111104
28°F169162158154150146141136127
24°F195187183178174170165160153
20°F223215209204200195190185178
16°F257248242237231226220214203

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
6,304
Cooling degree days, base 65°F
488
Growing degree days, base 40°F
4,490
Growing degree days, base 45°F
3,377
Growing degree days, base 50°F
2,432
Growing degree days, base 55°F
1,646
Growing degree days, base 60°F
996

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,15600
February90000
March76303
April542038
May2897207
June6174464
July2225688
August8158615
September13425346
October496069
November82502
December1,13000

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 14.2 km from Towaoc. 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 USW00093069 (Cortez Montezuma CO AP). Public domain.