Ashland climate

Ashland Frost Dates and Growing Season

NOAA 1991-2020 normals for Brandenberg, 24.9 km from Ashland, elevation 2770 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Brandenberg. 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 18 and the first fall freeze around September 22, a growing season of about 126 days.

Median at 36°F
last May 30, first September 10
Median at 32°F
last May 18, first September 22
Median at 28°F
last May 7, first October 2

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°FJun 15Jun 10Jun 6Jun 2May 30May 27May 25May 22May 17
32°FMay 30May 25May 22May 20May 18May 16May 14May 11May 6
28°FMay 19May 15May 12May 10May 7May 4May 2Apr 30Apr 25
24°FMay 9May 4May 1Apr 28Apr 25Apr 22Apr 18Apr 14Apr 8
20°FApr 30Apr 25Apr 21Apr 17Apr 13Apr 10Apr 6Apr 2Mar 28
16°FApr 22Apr 15Apr 11Apr 7Apr 3Mar 31Mar 26Mar 19Mar 12

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°FAug 27Sep 1Sep 5Sep 8Sep 10Sep 13Sep 17Sep 21Sep 26
32°FSep 8Sep 12Sep 16Sep 19Sep 22Sep 25Sep 28Oct 1Oct 5
28°FSep 17Sep 23Sep 26Sep 30Oct 2Oct 4Oct 7Oct 12Oct 16
24°FSep 27Oct 2Oct 6Oct 10Oct 13Oct 16Oct 19Oct 23Oct 27
20°FOct 5Oct 12Oct 16Oct 20Oct 23Oct 26Oct 28Oct 31Nov 6
16°FOct 17Oct 22Oct 26Oct 29Nov 1Nov 4Nov 7Nov 11Nov 17

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°F12111511010610398948881
32°F145138134129126123119114107
28°F165158154151148144140136128
24°F191184179174170166161156149
20°F213205200196191187182176169
16°F237228222217212206201195188

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
7,253
Cooling degree days, base 65°F
582
Growing degree days, base 40°F
4,402
Growing degree days, base 45°F
3,339
Growing degree days, base 50°F
2,433
Growing degree days, base 55°F
1,673
Growing degree days, base 60°F
1,056

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,30400
February1,08200
March88709
April581049
May31710199
June9172433
July13243696
August27208647
September18545325
October570371
November93506
December1,26300

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 24.9 km from Ashland. 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 USC00241084 (Brandenberg). Public domain.