Mora climate

Mora Frost Dates and Growing Season

NOAA 1991-2020 normals for Gascon, 14 km from Mora, elevation 8250 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Gascon. 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 28 and the first fall freeze around September 26, a growing season of about 119 days.

Median at 36°F
last June 8, first September 16
Median at 32°F
last May 28, first September 26
Median at 28°F
last May 14, first October 5

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 23Jun 17Jun 14Jun 11Jun 8Jun 6Jun 3Jun 1May 28
32°FJun 10Jun 6Jun 3May 31May 28May 25May 21May 18May 13
28°FMay 30May 24May 20May 17May 14May 11May 7May 3Apr 29
24°FMay 16May 12May 8May 5May 2Apr 29Apr 26Apr 22Apr 16
20°FMay 8May 2Apr 28Apr 25Apr 21Apr 18Apr 14Apr 9Apr 4
16°FApr 29Apr 23Apr 19Apr 15Apr 10Apr 6Apr 3Mar 28Mar 17

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 3Sep 7Sep 10Sep 13Sep 16Sep 18Sep 20Sep 24Sep 29
32°FSep 12Sep 16Sep 20Sep 23Sep 26Sep 28Oct 1Oct 3Oct 7
28°FSep 22Sep 27Sep 30Oct 2Oct 5Oct 7Oct 9Oct 12Oct 17
24°FOct 2Oct 6Oct 9Oct 11Oct 14Oct 17Oct 20Oct 23Oct 28
20°FOct 10Oct 15Oct 19Oct 22Oct 26Oct 29Nov 1Nov 4Nov 8
16°FOct 19Oct 24Oct 29Nov 1Nov 3Nov 6Nov 10Nov 14Nov 20

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°F1141091041019793898478
32°F138132127123119115111106100
28°F161155150147143138134129122
24°F185179174170166162157152145
20°F209200195190186181176170163
16°F235224217212207202197191183

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
7,080
Cooling degree days, base 65°F
22
Growing degree days, base 40°F
3,201
Growing degree days, base 45°F
2,130
Growing degree days, base 50°F
1,275
Growing degree days, base 55°F
623
Growing degree days, base 60°F
187

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,04600
February90600
March84503
April663012
May446193
June1828279
July1129363
August1534316
September2981168
October563040
November81802
December1,05100

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 km from Mora. 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 USC00293488 (Gascon). Public domain.