Robesonia climate

Robesonia Frost Dates and Growing Season

NOAA 1991-2020 normals for Blue Marsh Lake, 9.6 km from Robesonia, elevation 350 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Blue Marsh Lake. 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 26 and the first fall freeze around October 19, a growing season of about 176 days.

Median at 36°F
last May 8, first October 8
Median at 32°F
last April 26, first October 19
Median at 28°F
last April 12, first November 1

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 23May 18May 14May 10May 8May 5May 1Apr 29Apr 22
32°FMay 12May 7May 4Apr 30Apr 26Apr 23Apr 19Apr 16Apr 11
28°FMay 1Apr 23Apr 18Apr 15Apr 12Apr 9Apr 6Apr 3Mar 30
24°FApr 15Apr 9Apr 5Apr 2Mar 31Mar 29Mar 25Mar 21Mar 15
20°FApr 2Mar 30Mar 26Mar 22Mar 18Mar 15Mar 12Mar 7Mar 2
16°FMar 24Mar 19Mar 15Mar 11Mar 8Mar 5Mar 1Feb 25Feb 18

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 26Oct 1Oct 3Oct 6Oct 8Oct 11Oct 14Oct 18Oct 23
32°FOct 5Oct 9Oct 13Oct 16Oct 19Oct 23Oct 27Oct 30Nov 3
28°FOct 15Oct 22Oct 26Oct 30Nov 1Nov 3Nov 5Nov 8Nov 13
24°FOct 30Nov 3Nov 5Nov 9Nov 12Nov 15Nov 18Nov 22Nov 27
20°FNov 8Nov 13Nov 17Nov 21Nov 24Nov 28Dec 1Dec 5Dec 12
16°FNov 19Nov 28Dec 1Dec 5Dec 9Dec 13Dec 18Dec 23Dec 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°F174167161157154149144140134
32°F198191185180176171166161152
28°F221215210206202198193188179
24°F247240235230226222218214207
20°F273265259254249246241235228
16°F300292286280275269264258250

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
5,717
Cooling degree days, base 65°F
843
Growing degree days, base 40°F
5,374
Growing degree days, base 45°F
4,182
Growing degree days, base 50°F
3,139
Growing degree days, base 55°F
2,229
Growing degree days, base 60°F
1,464

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,13602
February97302
March816018
April4545108
May19144326
June34164581
July3291753
August6237696
September8592460
October37310161
November674028
December97504

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 9.6 km from Robesonia. 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 USC00360785 (Blue Marsh Lake). Public domain.