Marvin climate

Marvin Frost Dates and Growing Season

NOAA 1991-2020 normals for Monroe AP, 17.9 km from Marvin, elevation 679 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Monroe AP. 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 March 31 and the first fall freeze around November 5, a growing season of about 220 days.

Median at 36°F
last April 12, first October 27
Median at 32°F
last March 31, first November 5
Median at 28°F
last March 16, first November 16

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

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°F217211206201197194189184178
32°F244236230225220215211206199
28°F273263257251246241235230220
24°F314302293285276270263256248
20°F346334327318310303296287273
16°F365365359349340334328317306

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
98% of years
16°F or colder
79% 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
3,061
Cooling degree days, base 65°F
1,715
Growing degree days, base 40°F
7,976
Growing degree days, base 45°F
6,403
Growing degree days, base 50°F
4,989
Growing degree days, base 55°F
3,730
Growing degree days, base 60°F
2,638

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January702042
February541259
March39710158
April16848342
May39157583
June1339787
July0454919
August0409874
September14237673
October15352372
November4165124
December629256

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 17.9 km from Marvin. 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 USW00053872 (Monroe AP). Public domain.