Waverly climate

Waverly Frost Dates and Growing Season

NOAA 1991-2020 normals for Waverly, 1 km from Waverly, elevation 800 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Waverly. 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 6 and the first fall freeze around October 30, a growing season of about 207 days.

Median at 36°F
last April 18, first October 21
Median at 32°F
last April 6, first October 30
Median at 28°F
last March 28, first November 8

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 3Apr 29Apr 25Apr 21Apr 18Apr 15Apr 12Apr 8Apr 3
32°FApr 23Apr 17Apr 12Apr 9Apr 6Apr 3Mar 31Mar 28Mar 21
28°FApr 11Apr 5Apr 2Mar 31Mar 28Mar 24Mar 21Mar 17Mar 11
24°FApr 3Mar 29Mar 24Mar 20Mar 17Mar 14Mar 10Mar 6Mar 1
20°FMar 23Mar 18Mar 14Mar 11Mar 7Mar 4Mar 1Feb 25Feb 19
16°FMar 16Mar 11Mar 7Mar 4Mar 1Feb 27Feb 23Feb 18Feb 9

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 8Oct 14Oct 17Oct 19Oct 21Oct 23Oct 26Oct 29Nov 1
32°FOct 18Oct 22Oct 25Oct 28Oct 30Nov 1Nov 4Nov 7Nov 13
28°FOct 28Nov 1Nov 2Nov 5Nov 8Nov 11Nov 14Nov 19Nov 25
24°FNov 2Nov 7Nov 10Nov 14Nov 17Nov 21Nov 25Dec 1Dec 5
20°FNov 9Nov 15Nov 19Nov 24Nov 28Dec 1Dec 5Dec 9Dec 16
16°FNov 18Nov 25Nov 29Dec 3Dec 7Dec 11Dec 15Dec 21Dec 27

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°F205198194190186182178174165
32°F228220214211207203199194187
28°F249241235231227222217211205
24°F271263257252247241237231222
20°F289280275269264261254249241
16°F307297292286281277272266258

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
5,075
Cooling degree days, base 65°F
1,325
Growing degree days, base 40°F
6,423
Growing degree days, base 45°F
5,136
Growing degree days, base 50°F
3,982
Growing degree days, base 55°F
2,964
Growing degree days, base 60°F
2,079

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,12202
February89609
March658466
April33313195
May116102459
June5275720
July1393857
August1342806
September53164561
October28632253
November629251
December97605

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 km from Waverly. 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 USC00238770 (Waverly). Public domain.