Morrisonville climate

Morrisonville Frost Dates and Growing Season

NOAA 1991-2020 normals for Morrisonville, 0.7 km from Morrisonville, elevation 630 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Morrisonville. 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 12 and the first fall freeze around October 20, a growing season of about 190 days.

Median at 36°F
last April 24, first October 9
Median at 32°F
last April 12, first October 20
Median at 28°F
last April 1, first October 31

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 10May 4Apr 30Apr 27Apr 24Apr 21Apr 18Apr 14Apr 9
32°FApr 27Apr 21Apr 17Apr 15Apr 12Apr 8Apr 5Apr 2Mar 29
28°FApr 16Apr 11Apr 6Apr 3Apr 1Mar 30Mar 26Mar 22Mar 17
24°FApr 6Apr 1Mar 29Mar 25Mar 22Mar 19Mar 16Mar 11Mar 5
20°FMar 29Mar 23Mar 19Mar 16Mar 13Mar 10Mar 6Mar 2Feb 24
16°FMar 20Mar 15Mar 12Mar 8Mar 5Mar 1Feb 26Feb 19Feb 9

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 26Sep 30Oct 4Oct 7Oct 9Oct 12Oct 15Oct 18Oct 23
32°FOct 5Oct 11Oct 15Oct 18Oct 20Oct 22Oct 26Oct 29Nov 1
28°FOct 17Oct 22Oct 26Oct 29Oct 31Nov 3Nov 6Nov 11Nov 16
24°FOct 29Nov 1Nov 4Nov 8Nov 11Nov 15Nov 19Nov 24Nov 30
20°FNov 5Nov 10Nov 15Nov 20Nov 25Nov 28Dec 1Dec 6Dec 13
16°FNov 14Nov 21Nov 27Nov 30Dec 4Dec 8Dec 12Dec 18Dec 24

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°F188180176171167163159153144
32°F211204199194190186181176169
28°F236228222218213209205200192
24°F262253245240236231226221213
20°F283275269263258252246240232
16°F305295288282277272266260251

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
5,322
Cooling degree days, base 65°F
1,206
Growing degree days, base 40°F
6,161
Growing degree days, base 45°F
4,916
Growing degree days, base 50°F
3,803
Growing degree days, base 55°F
2,813
Growing degree days, base 60°F
1,942

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,16402
February92405
March718352
April35018190
May115104458
June13259696
July1344808
August4298759
September60154546
October30726233
November665149
December1,00406

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 Morrisonville. 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 USC00115841 (Morrisonville). Public domain.