Monroe climate

Monroe Frost Dates and Growing Season

NOAA 1991-2020 normals for Monroe 2 Se, 2.4 km from Monroe, elevation 550 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Monroe 2 Se. 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 3 and the first fall freeze around November 1, a growing season of about 213 days.

Median at 36°F
last April 14, first October 25
Median at 32°F
last April 3, first November 1
Median at 28°F
last March 23, first November 10

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°FApr 29Apr 24Apr 20Apr 17Apr 14Apr 10Apr 8Apr 5Mar 31
32°FApr 18Apr 13Apr 8Apr 5Apr 3Mar 31Mar 28Mar 23Mar 17
28°FApr 7Apr 2Mar 30Mar 27Mar 23Mar 19Mar 15Mar 10Mar 1
24°FMar 28Mar 23Mar 17Mar 13Mar 8Mar 4Feb 28Feb 23Feb 14
20°FMar 16Mar 8Mar 3Feb 28Feb 22Feb 15Feb 8Jan 31Jan 23
16°FMar 6Feb 28Feb 18Feb 8Feb 2Jan 29Jan 22Jan 14Jan 2

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°FOct 12Oct 16Oct 20Oct 23Oct 25Oct 27Oct 30Nov 1Nov 5
32°FOct 21Oct 25Oct 28Oct 31Nov 1Nov 4Nov 6Nov 9Nov 14
28°FOct 30Nov 1Nov 5Nov 7Nov 10Nov 13Nov 17Nov 22Nov 29
24°FNov 6Nov 10Nov 14Nov 18Nov 22Nov 26Dec 1Dec 6Dec 19
20°FNov 16Nov 24Nov 30Dec 4Dec 9Dec 16Dec 26Jan 2Jan 10
16°FDec 1Dec 8Dec 17Dec 25Jan 1Jan 6Jan 11Jan 18Jan 30

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°F214206201197193189184180174
32°F233225219216213209205200194
28°F258249243238234229224219213
24°F293281273266259254248241234
20°F332318307300293285277269256
16°F365352340334327318309300289

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
99% of years
16°F or colder
89% 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
3,199
Cooling degree days, base 65°F
1,735
Growing degree days, base 40°F
7,881
Growing degree days, base 45°F
6,332
Growing degree days, base 50°F
4,942
Growing degree days, base 55°F
3,710
Growing degree days, base 60°F
2,640

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January723035
February568146
March4307140
April18144327
May43160582
June3346793
July0464928
August0416880
September15238673
October15654371
November4355116
December646150

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 2.4 km from Monroe. 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 USC00315771 (Monroe 2 Se). Public domain.