Avondale climate

Avondale Frost Dates and Growing Season

NOAA 1991-2020 normals for Avondale 2 N, 4 km from Avondale, elevation 400 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Avondale 2 N. 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 19 and the first fall freeze around October 26, a growing season of about 189 days.

Median at 36°F
last April 30, first October 13
Median at 32°F
last April 19, first October 26
Median at 28°F
last April 5, 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 14May 10May 6May 2Apr 30Apr 27Apr 24Apr 21Apr 17
32°FMay 3Apr 28Apr 24Apr 22Apr 19Apr 16Apr 12Apr 8Apr 1
28°FApr 19Apr 15Apr 11Apr 8Apr 5Apr 2Mar 31Mar 27Mar 22
24°FApr 7Apr 2Mar 30Mar 27Mar 24Mar 21Mar 18Mar 13Mar 8
20°FMar 27Mar 22Mar 19Mar 15Mar 12Mar 8Mar 5Mar 1Feb 23
16°FMar 17Mar 13Mar 8Mar 4Mar 1Feb 26Feb 21Feb 14Feb 7

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°FOct 3Oct 5Oct 8Oct 11Oct 13Oct 16Oct 18Oct 22Oct 28
32°FOct 11Oct 15Oct 19Oct 23Oct 26Oct 28Nov 1Nov 3Nov 8
28°FOct 21Oct 26Oct 31Nov 2Nov 4Nov 8Nov 11Nov 15Nov 21
24°FNov 3Nov 9Nov 12Nov 15Nov 18Nov 21Nov 25Dec 1Dec 4
20°FNov 13Nov 18Nov 23Nov 28Dec 1Dec 5Dec 8Dec 14Dec 21
16°FNov 25Dec 2Dec 7Dec 12Dec 17Dec 22Dec 27Jan 1Jan 9

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°F186179173169165162158152147
32°F209203198194189185179175167
28°F234227222218214210205200192
24°F263255248242238234229224218
20°F291282275270264260255249241
16°F317308302298292286280274266

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
5,359
Cooling degree days, base 65°F
778
Growing degree days, base 40°F
5,475
Growing degree days, base 45°F
4,229
Growing degree days, base 50°F
3,143
Growing degree days, base 55°F
2,208
Growing degree days, base 60°F
1,417

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,06503
February90706
March763026
April4327117
May17239338
June24151578
July2270733
August6214673
September7987458
October35610173
November636032
December91807

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 4 km from Avondale. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USW00003761 (Avondale 2 N). Public domain.