Fallon Station climate

Fallon Station Frost Dates and Growing Season

NOAA 1991-2020 normals for Fallon Naas, 0.1 km from Fallon Station, elevation 3934 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Fallon Naas. 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 6 and the first fall freeze around October 8, a growing season of about 153 days.

Median at 36°F
last May 21, first September 29
Median at 32°F
last May 6, first October 8
Median at 28°F
last April 24, first October 17

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 9Jun 3May 31May 26May 21May 17May 13May 8May 2
32°FMay 25May 18May 14May 10May 6May 3Apr 30Apr 26Apr 21
28°FMay 11May 4Apr 30Apr 27Apr 24Apr 20Apr 17Apr 14Apr 9
24°FApr 28Apr 21Apr 17Apr 13Apr 9Apr 5Mar 31Mar 25Mar 16
20°FApr 9Apr 4Mar 30Mar 23Mar 16Mar 10Mar 5Feb 28Feb 18
16°FMar 20Mar 8Mar 2Feb 27Feb 22Feb 16Feb 10Feb 2Jan 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 13Sep 19Sep 23Sep 26Sep 29Oct 1Oct 3Oct 6Oct 11
32°FSep 25Sep 30Oct 3Oct 5Oct 8Oct 10Oct 13Oct 16Oct 21
28°FOct 5Oct 9Oct 13Oct 15Oct 17Oct 20Oct 23Oct 27Nov 1
24°FOct 14Oct 19Oct 22Oct 25Oct 28Oct 31Nov 3Nov 6Nov 11
20°FOct 23Oct 28Nov 1Nov 4Nov 7Nov 11Nov 15Nov 19Nov 23
16°FOct 31Nov 6Nov 12Nov 16Nov 20Nov 24Nov 27Dec 1Dec 9

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°F151143137132127123118112104
32°F175167161156153149143136129
28°F197190184180176172166161154
24°F227218212207201196191187178
20°F265253247241235230222215204
16°F307293283277270263256249239

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
5,088
Cooling degree days, base 65°F
1,004
Growing degree days, base 40°F
5,705
Growing degree days, base 45°F
4,411
Growing degree days, base 50°F
3,309
Growing degree days, base 55°F
2,389
Growing degree days, base 60°F
1,629

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January95301
February72905
March594035
April4172109
May19939318
June47165568
July1381844
August4304766
September71106488
October3727160
November712014
December98901

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 0.1 km from Fallon Station. 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 USW00093102 (Fallon Naas). Public domain.