Robbinston climate

Robbinston Frost Dates and Growing Season

NOAA 1991-2020 normals for Robbinston, 1.2 km from Robbinston, elevation 115 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Robbinston. 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 May 5 and the first fall freeze around October 13, a growing season of about 160 days.

Median at 36°F
last May 19, first October 1
Median at 32°F
last May 5, first October 13
Median at 28°F
last April 21, first October 28

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 31May 26May 23May 21May 19May 16May 14May 10May 6
32°FMay 18May 13May 10May 7May 5May 2Apr 30Apr 28Apr 24
28°FMay 3Apr 30Apr 27Apr 24Apr 21Apr 18Apr 15Apr 11Apr 7
24°FApr 21Apr 17Apr 14Apr 10Apr 8Apr 5Apr 3Apr 1Mar 27
20°FApr 13Apr 7Apr 5Apr 3Apr 1Mar 30Mar 25Mar 22Mar 17
16°FApr 5Apr 2Mar 30Mar 26Mar 23Mar 20Mar 17Mar 14Mar 10

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 19Sep 24Sep 27Sep 29Oct 1Oct 4Oct 6Oct 10Oct 15
32°FOct 1Oct 4Oct 7Oct 10Oct 13Oct 16Oct 20Oct 24Oct 30
28°FOct 11Oct 16Oct 21Oct 24Oct 28Oct 31Nov 2Nov 5Nov 9
24°FOct 27Oct 31Nov 3Nov 6Nov 8Nov 11Nov 14Nov 18Nov 23
20°FNov 7Nov 11Nov 14Nov 17Nov 20Nov 23Nov 26Nov 29Dec 3
16°FNov 15Nov 20Nov 24Nov 27Nov 30Dec 1Dec 4Dec 7Dec 13

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°F153146142138135132128124118
32°F179172167163160156151147141
28°F207200194190187183178173167
24°F233227222218214210206201193
20°F252245241237233230226222215
16°F267261256253249245241236229

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
7,745
Cooling degree days, base 65°F
209
Growing degree days, base 40°F
3,635
Growing degree days, base 45°F
2,633
Growing degree days, base 50°F
1,787
Growing degree days, base 55°F
1,097
Growing degree days, base 60°F
563

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,40000
February1,20000
March1,06201
April70708
May4142102
June16022314
July4086511
August3879505
September19920278
October527059
November81907
December1,18100

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 1.2 km from Robbinston. 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 USC00177238 (Robbinston). Public domain.