Chama climate

Chama Frost Dates and Growing Season

NOAA 1991-2020 normals for Chama, 1.6 km from Chama, elevation 7850 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Chama. 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 June 14 and the first fall freeze around September 18, a growing season of about 93 days.

Median at 32°F
last June 14, first September 18
Median at 28°F
last June 1, first September 26

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°F–––––––––
32°FJun 30Jun 25Jun 21Jun 18Jun 14Jun 11Jun 8Jun 5Jun 1
28°FJun 17Jun 12Jun 7Jun 4Jun 1May 30May 26May 21May 16
24°FJun 4May 30May 25May 20May 16May 12May 9May 4Apr 30
20°FMay 19May 12May 7May 4May 1Apr 28Apr 24Apr 21Apr 16
16°FMay 4Apr 29Apr 25Apr 21Apr 18Apr 15Apr 12Apr 8Apr 3

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°F–––––––––
32°FSep 7Sep 11Sep 14Sep 16Sep 18Sep 21Sep 23Sep 25Sep 29
28°FSep 14Sep 19Sep 22Sep 24Sep 26Sep 29Oct 1Oct 4Oct 8
24°FSep 22Sep 26Sep 29Oct 1Oct 4Oct 6Oct 8Oct 12Oct 17
20°FSep 29Oct 3Oct 6Oct 9Oct 13Oct 16Oct 19Oct 24Oct 28
16°FOct 4Oct 11Oct 16Oct 19Oct 23Oct 27Oct 30Nov 3Nov 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°F878277747065615545
32°F110104101979390868275
28°F13913212612111711310910498
24°F163155150145140136131126118
20°F185178173168164160155150143
16°F210202196192187182177172163

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
8,319
Cooling degree days, base 65°F
33
Growing degree days, base 40°F
2,909
Growing degree days, base 45°F
1,990
Growing degree days, base 50°F
1,239
Growing degree days, base 55°F
648
Growing degree days, base 60°F
229

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,32400
February1,09800
March98100
April74403
May512051
June2243235
July7620409
August11210363
September3090163
October656015
November98100
December1,30400

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 1.6 km from Chama. 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 USC00291664 (Chama). Public domain.