Byron climate

Byron Frost Dates and Growing Season

NOAA 1991-2020 normals for Linden Wwtp, 11.5 km from Byron, elevation 863 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Linden Wwtp. 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 3 and the first fall freeze around October 12, a growing season of about 161 days.

Median at 36°F
last May 15, first October 1
Median at 32°F
last May 3, first October 12
Median at 28°F
last April 23, first October 27

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 30May 25May 22May 18May 15May 11May 7May 3Apr 30
32°FMay 20May 15May 10May 5May 3Apr 30Apr 28Apr 24Apr 21
28°FMay 9May 2Apr 29Apr 26Apr 23Apr 20Apr 17Apr 14Apr 10
24°FApr 23Apr 19Apr 16Apr 13Apr 11Apr 8Apr 5Apr 2Mar 31
20°FApr 14Apr 7Apr 4Apr 2Mar 31Mar 29Mar 25Mar 21Mar 16
16°FApr 3Mar 31Mar 27Mar 24Mar 21Mar 18Mar 16Mar 13Mar 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°FSep 20Sep 23Sep 26Sep 29Oct 1Oct 3Oct 5Oct 8Oct 13
32°FSep 30Oct 3Oct 7Oct 10Oct 12Oct 15Oct 19Oct 22Oct 28
28°FOct 10Oct 16Oct 20Oct 23Oct 27Oct 30Nov 1Nov 4Nov 9
24°FOct 24Oct 30Nov 1Nov 4Nov 7Nov 10Nov 13Nov 17Nov 24
20°FNov 5Nov 9Nov 14Nov 18Nov 21Nov 25Nov 28Dec 1Dec 7
16°FNov 15Nov 21Nov 25Nov 28Dec 1Dec 4Dec 8Dec 13Dec 19

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°F157151146142138135132127119
32°F181174169165161157153147141
28°F205199194189185181175170163
24°F231223218214210206201197190
20°F255248242238234230225220214
16°F277269263259255250246240233

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
7,065
Cooling degree days, base 65°F
465
Growing degree days, base 40°F
4,400
Growing degree days, base 45°F
3,342
Growing degree days, base 50°F
2,422
Growing degree days, base 55°F
1,633
Growing degree days, base 60°F
972

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,31700
February1,14900
March993113
April611253
May28728241
June6295484
July19161607
August30126561
September16347342
October4886103
November795016
December1,15201

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 11.5 km from Byron. 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 USC00204793 (Linden Wwtp). Public domain.