Fairfield climate

Fairfield Frost Dates and Growing Season

NOAA 1991-2020 normals for Waterville Trtmt Plt, 8.1 km from Fairfield, elevation 73 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Waterville Trtmt Plt. 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 2 and the first fall freeze around October 10, a growing season of about 159 days.

Median at 36°F
last May 14, first October 1
Median at 32°F
last May 2, first October 10
Median at 28°F
last April 22, first October 24

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°FMay 27May 22May 20May 17May 14May 12May 9May 6May 3
32°FMay 14May 10May 7May 5May 2May 1Apr 29Apr 27Apr 23
28°FMay 3Apr 30Apr 27Apr 24Apr 22Apr 19Apr 17Apr 14Apr 10
24°FApr 21Apr 17Apr 13Apr 11Apr 8Apr 6Apr 5Apr 3Mar 31
20°FApr 12Apr 7Apr 5Apr 3Apr 2Mar 31Mar 28Mar 23Mar 19
16°FApr 6Apr 2Mar 31Mar 28Mar 25Mar 22Mar 19Mar 15Mar 11

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 19Sep 23Sep 26Sep 29Oct 1Oct 2Oct 4Oct 7Oct 11
32°FSep 30Oct 2Oct 5Oct 7Oct 10Oct 13Oct 17Oct 20Oct 27
28°FOct 7Oct 13Oct 17Oct 21Oct 24Oct 27Oct 30Nov 2Nov 7
24°FOct 21Oct 26Oct 30Nov 1Nov 4Nov 7Nov 11Nov 15Nov 19
20°FNov 1Nov 7Nov 11Nov 15Nov 18Nov 20Nov 23Nov 26Nov 30
16°FNov 12Nov 18Nov 21Nov 24Nov 26Nov 28Dec 1Dec 3Dec 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°F154148144141137133130126119
32°F176170165162159155152148141
28°F201195190187183179176171165
24°F224218214211208204200196190
20°F247240236232228225221216209
16°F264258253250246243239234228

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
7,596
Cooling degree days, base 65°F
394
Growing degree days, base 40°F
4,086
Growing degree days, base 45°F
3,076
Growing degree days, base 50°F
2,201
Growing degree days, base 55°F
1,456
Growing degree days, base 60°F
846

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,43700
February1,23600
March1,07302
April665024
May3349173
June9461418
July15158608
August23130572
September16735324
October511174
November82807
December1,21400

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 8.1 km from Fairfield. 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 USC00179151 (Waterville Trtmt Plt). Public domain.