Alma climate

Alma Frost Dates and Growing Season

NOAA 1991-2020 normals for Oswayo 1 Ene, 10.7 km from Alma, elevation 1710 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Oswayo 1 Ene. 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 20 and the first fall freeze around September 29, a growing season of about 130 days.

Median at 36°F
last June 2, first September 17
Median at 32°F
last May 20, first September 29
Median at 28°F
last May 6, first October 9

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 14Jun 8Jun 4Jun 2May 31May 28May 24May 18
32°FJun 2May 30May 27May 24May 20May 17May 13May 10May 5
28°FMay 25May 19May 14May 10May 6May 4May 1Apr 28Apr 25
24°FMay 13May 6May 2Apr 29Apr 27Apr 24Apr 22Apr 19Apr 14
20°FApr 28Apr 23Apr 21Apr 18Apr 16Apr 13Apr 9Apr 5Apr 2
16°FApr 17Apr 12Apr 8Apr 6Apr 4Apr 2Mar 31Mar 27Mar 21

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 2Sep 6Sep 10Sep 14Sep 17Sep 20Sep 23Sep 27Oct 1
32°FSep 14Sep 19Sep 23Sep 26Sep 29Oct 1Oct 3Oct 6Oct 10
28°FSep 26Oct 1Oct 3Oct 6Oct 9Oct 13Oct 16Oct 19Oct 25
24°FOct 7Oct 13Oct 18Oct 21Oct 24Oct 28Nov 1Nov 4Nov 9
20°FOct 23Oct 29Nov 1Nov 3Nov 6Nov 9Nov 11Nov 14Nov 19
16°FNov 4Nov 8Nov 11Nov 14Nov 16Nov 18Nov 22Nov 25Dec 1

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°F12411711210710398938774
32°F150142138134130126122116109
28°F174167162157153150145140133
24°F199192187182178174170164156
20°F224217212208205201196192184
16°F247240234229226223219214207

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
7,781
Cooling degree days, base 65°F
210
Growing degree days, base 40°F
3,721
Growing degree days, base 45°F
2,723
Growing degree days, base 50°F
1,860
Growing degree days, base 55°F
1,136
Growing degree days, base 60°F
578

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,37500
February1,19600
March1,06607
April687035
May3579177
June11742378
July5482493
August7259453
September23817244
October563068
November87607
December1,18100

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 10.7 km from Alma. 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 USC00366649 (Oswayo 1 Ene). Public domain.