Amherst climate

Amherst Frost Dates and Growing Season

NOAA 1991-2020 normals for Elyria Lorain CO AP, 6.8 km from Amherst, elevation 794 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Elyria Lorain CO 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 April 24 and the first fall freeze around October 24, a growing season of about 182 days.

Median at 36°F
last May 5, first October 10
Median at 32°F
last April 24, first October 24
Median at 28°F
last April 11, first November 4

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 19May 15May 11May 8May 5May 2Apr 30Apr 26Apr 21
32°FMay 10May 4Apr 30Apr 27Apr 24Apr 21Apr 18Apr 14Apr 9
28°FApr 26Apr 21Apr 18Apr 15Apr 11Apr 8Apr 4Apr 2Mar 29
24°FApr 15Apr 10Apr 5Apr 2Mar 31Mar 28Mar 24Mar 20Mar 17
20°FApr 4Mar 31Mar 28Mar 24Mar 21Mar 18Mar 15Mar 10Mar 4
16°FMar 28Mar 22Mar 18Mar 15Mar 11Mar 8Mar 5Mar 1Feb 23

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 28Oct 2Oct 5Oct 7Oct 10Oct 13Oct 17Oct 20Oct 26
32°FOct 8Oct 13Oct 17Oct 21Oct 24Oct 27Oct 31Nov 2Nov 6
28°FOct 21Oct 27Oct 31Nov 2Nov 4Nov 7Nov 11Nov 15Nov 19
24°FNov 3Nov 7Nov 10Nov 13Nov 16Nov 20Nov 24Nov 28Dec 4
20°FNov 10Nov 15Nov 19Nov 24Nov 28Dec 1Dec 5Dec 9Dec 16
16°FNov 19Nov 27Dec 1Dec 4Dec 8Dec 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°F178171166162157153149144139
32°F204196191187182177173168160
28°F229221216212208203199194185
24°F254246238233229225221216209
20°F279269262258252247242236228
16°F298290283278273268262256247

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
6,045
Cooling degree days, base 65°F
690
Growing degree days, base 40°F
5,125
Growing degree days, base 45°F
3,955
Growing degree days, base 50°F
2,930
Growing degree days, base 55°F
2,041
Growing degree days, base 60°F
1,289

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,18702
February1,01503
March868124
April497699
May21548314
June39156567
July5230690
August14171622
September10367416
October38611157
November701031
December1,01506

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 6.8 km from Amherst. 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 USW00004849 (Elyria Lorain CO AP). Public domain.