Rossford climate

Rossford Frost Dates and Growing Season

NOAA 1991-2020 normals for Toledo Metcalf Fld, 9 km from Rossford, elevation 622 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Toledo Metcalf Fld. 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 20 and the first fall freeze around October 27, a growing season of about 188 days.

Median at 36°F
last May 1, first October 15
Median at 32°F
last April 20, first October 27
Median at 28°F
last April 8, first November 7

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 16May 11May 7May 4May 1Apr 29Apr 25Apr 22Apr 17
32°FMay 7May 1Apr 27Apr 23Apr 20Apr 17Apr 14Apr 10Apr 5
28°FApr 25Apr 20Apr 16Apr 12Apr 8Apr 4Apr 2Mar 31Mar 25
24°FApr 13Apr 6Apr 3Mar 31Mar 29Mar 26Mar 23Mar 19Mar 14
20°FApr 1Mar 29Mar 26Mar 22Mar 19Mar 16Mar 14Mar 9Mar 3
16°FMar 27Mar 21Mar 17Mar 14Mar 10Mar 7Mar 3Feb 27Feb 19

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 1Oct 5Oct 9Oct 12Oct 15Oct 18Oct 21Oct 24Oct 28
32°FOct 14Oct 19Oct 22Oct 25Oct 27Oct 30Nov 1Nov 4Nov 9
28°FOct 26Nov 1Nov 2Nov 4Nov 7Nov 10Nov 13Nov 16Nov 21
24°FNov 4Nov 7Nov 11Nov 14Nov 17Nov 20Nov 24Nov 29Dec 5
20°FNov 11Nov 16Nov 20Nov 24Nov 27Dec 1Dec 5Dec 10Dec 17
16°FNov 19Nov 25Nov 30Dec 4Dec 8Dec 12Dec 17Dec 22Dec 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°F185178174170165162157152146
32°F209202197192188184180176167
28°F231224219215211208203198190
24°F256249243238233229226220214
20°F278270263258254249245239231
16°F300291285279274269263258249

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
5,839
Cooling degree days, base 65°F
930
Growing degree days, base 40°F
5,518
Growing degree days, base 45°F
4,332
Growing degree days, base 50°F
3,283
Growing degree days, base 55°F
2,367
Growing degree days, base 60°F
1,583

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,18302
February1,00503
March840125
April4676105
May17860356
June22200628
July1302766
August4247708
September7997469
October35416180
November686035
December1,02206

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 9 km from Rossford. 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 USW00004848 (Toledo Metcalf Fld). Public domain.