Jay climate

Jay Frost Dates and Growing Season

NOAA 1991-2020 normals for Upper Spavinaw Port, 8.5 km from Jay, elevation 795 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Upper Spavinaw Port. 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 April 16 and the first fall freeze around October 20, a growing season of about 187 days.

Median at 36°F
last April 28, first October 10
Median at 32°F
last April 16, first October 20
Median at 28°F
last April 3, first October 30

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 11May 6May 3Apr 30Apr 28Apr 25Apr 22Apr 17Apr 12
32°FMay 1Apr 27Apr 23Apr 19Apr 16Apr 13Apr 10Apr 6Mar 31
28°FApr 21Apr 15Apr 10Apr 7Apr 3Mar 31Mar 28Mar 22Mar 16
24°FApr 8Apr 3Mar 30Mar 26Mar 22Mar 18Mar 13Mar 7Mar 1
20°FMar 29Mar 23Mar 18Mar 13Mar 9Mar 4Feb 28Feb 25Feb 19
16°FMar 20Mar 12Mar 7Mar 3Feb 28Feb 24Feb 19Feb 13Feb 5

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 28Oct 3Oct 5Oct 8Oct 10Oct 13Oct 15Oct 18Oct 22
32°FOct 6Oct 11Oct 15Oct 18Oct 20Oct 22Oct 25Oct 28Nov 1
28°FOct 16Oct 20Oct 24Oct 27Oct 30Nov 1Nov 4Nov 7Nov 13
24°FOct 23Oct 30Nov 2Nov 6Nov 9Nov 13Nov 17Nov 22Nov 29
20°FNov 3Nov 9Nov 14Nov 19Nov 23Nov 27Dec 1Dec 6Dec 12
16°FNov 15Nov 24Nov 29Dec 1Dec 5Dec 10Dec 14Dec 21Dec 29

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°F185178173168165161157153147
32°F209200195191187183178173166
28°F230223218213208203200194188
24°F259248242237231226220215206
20°F285276268262255249243236226
16°F310300292286281275268262251

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
4,060
Cooling degree days, base 65°F
1,463
Growing degree days, base 40°F
7,044
Growing degree days, base 45°F
5,613
Growing degree days, base 50°F
4,339
Growing degree days, base 55°F
3,229
Growing degree days, base 60°F
2,271

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January907113
February695025
March522695
April25227259
May82102488
June3277724
July0433897
August1405869
September35179594
October24331275
November515380
December806021

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 8.5 km from Jay. 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 USC00349101 (Upper Spavinaw Port). Public domain.