Toomsuba climate

Toomsuba Frost Dates and Growing Season

NOAA 1991-2020 normals for Meridian Naas, 15.6 km from Toomsuba, elevation 271 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Meridian Naas. 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 March 14 and the first fall freeze around November 12, a growing season of about 245 days.

Median at 36°F
last March 30, first November 2
Median at 32°F
last March 14, first November 12
Median at 28°F
last February 27, first November 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°FApr 17Apr 10Apr 6Apr 3Mar 30Mar 26Mar 22Mar 16Mar 9
32°FApr 1Mar 26Mar 21Mar 17Mar 14Mar 10Mar 5Feb 28Feb 22
28°FMar 18Mar 13Mar 8Mar 3Feb 27Feb 23Feb 18Feb 10Jan 31
24°FMar 8Feb 28Feb 22Feb 15Feb 9Feb 2Jan 28Jan 22Jan 12
20°FFeb 25Feb 14Feb 7Jan 31Jan 28Jan 22Jan 16Jan 9Dec 31
16°FFeb 9Feb 3Jan 31Jan 25Jan 21Jan 17Jan 12Jan 7Jan 2

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 22Oct 25Oct 28Oct 31Nov 2Nov 4Nov 7Nov 11Nov 17
32°FOct 29Nov 2Nov 5Nov 8Nov 12Nov 16Nov 21Nov 26Dec 1
28°FNov 8Nov 13Nov 17Nov 22Nov 27Dec 1Dec 6Dec 15Dec 25
24°FNov 20Nov 28Dec 5Dec 14Dec 23Dec 30Jan 2Jan 9Jan 19
20°FDec 8Dec 22Dec 30Jan 1Jan 6Jan 10Jan 16Jan 24Feb 4
16°FDec 24Jan 1Jan 5Jan 9Jan 12Jan 17Jan 21Jan 28Feb 3

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°F242233227223218213208202195
32°F272262255250245239234228219
28°F309297289281275268261255246
24°F347334326318310303294285271
20°F365365362352343335329320306
16°F365365365365365365355343333

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
96% of years
20°F or colder
75% of years
16°F or colder
39% 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
2,132
Cooling degree days, base 65°F
2,488
Growing degree days, base 40°F
9,553
Growing degree days, base 45°F
7,854
Growing degree days, base 50°F
6,282
Growing degree days, base 55°F
4,854
Growing degree days, base 60°F
3,587

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January549589
February38711132
March24139293
April85100467
May12269722
June0454904
July05491,014
August0533998
September3364811
October83131516
November29923215
December47510121

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 15.6 km from Toomsuba. 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 USW00003866 (Meridian Naas). Public domain.