Saline climate

Saline Frost Dates and Growing Season

NOAA 1991-2020 normals for Saline Wwtp, 0.7 km from Saline, elevation 750 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Saline Wwtp. 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 11, a growing season of about 160 days.

Median at 36°F
last May 13, first October 1
Median at 32°F
last May 2, first October 11
Median at 28°F
last April 21, 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 28May 23May 19May 16May 13May 9May 6May 3Apr 28
32°FMay 18May 12May 8May 5May 2Apr 30Apr 26Apr 22Apr 17
28°FMay 7May 2Apr 28Apr 24Apr 21Apr 18Apr 15Apr 11Apr 7
24°FApr 22Apr 18Apr 14Apr 11Apr 8Apr 5Apr 2Mar 31Mar 27
20°FApr 13Apr 6Apr 3Apr 1Mar 31Mar 28Mar 24Mar 20Mar 15
16°FApr 2Mar 30Mar 27Mar 24Mar 21Mar 17Mar 15Mar 10Mar 4

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 18Sep 23Sep 26Sep 28Oct 1Oct 3Oct 5Oct 8Oct 13
32°FSep 29Oct 2Oct 5Oct 8Oct 11Oct 14Oct 17Oct 21Oct 26
28°FOct 7Oct 13Oct 17Oct 21Oct 24Oct 26Oct 29Nov 2Nov 7
24°FOct 20Oct 26Oct 30Nov 1Nov 4Nov 6Nov 10Nov 14Nov 19
20°FNov 1Nov 5Nov 9Nov 12Nov 15Nov 19Nov 23Nov 28Dec 3
16°FNov 9Nov 14Nov 19Nov 23Nov 27Dec 1Dec 4Dec 9Dec 18

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°F158152147142138134130126119
32°F181174169164160156153148141
28°F204197191187184179174168161
24°F230222216212209205199195187
20°F252244239234230226222216209
16°F276267262256250246241235230

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
6,698
Cooling degree days, base 65°F
598
Growing degree days, base 40°F
4,714
Growing degree days, base 45°F
3,629
Growing degree days, base 50°F
2,678
Growing degree days, base 55°F
1,855
Growing degree days, base 60°F
1,152

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,28501
February1,09601
March949114
April553270
May24130275
June42132540
July10215669
August17160607
September14055372
October4605116
November796011
December1,11001

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 0.7 km from Saline. 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 USC00207308 (Saline Wwtp). Public domain.