Sealy climate

Sealy Frost Dates and Growing Season

NOAA 1991-2020 normals for Sealy, 1.5 km from Sealy, elevation 196 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Sealy. 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 February 28 and the first fall freeze around November 30, a growing season of about 276 days.

Median at 36°F
last March 13, first November 17
Median at 32°F
last February 28, first November 30
Median at 28°F
last February 10, first December 20

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 5Mar 31Mar 23Mar 17Mar 13Mar 8Mar 3Feb 27Feb 20
32°FMar 21Mar 12Mar 8Mar 3Feb 28Feb 23Feb 17Feb 9Jan 30
28°FMar 9Mar 2Feb 25Feb 18Feb 10Feb 3Jan 28Jan 19Jan 2
24°FMar 1Feb 21Feb 9Feb 1Jan 28Jan 22Jan 10Jan 1Dec 22
20°FFeb 25Feb 15Feb 6Feb 1Jan 23Jan 14Jan 8Jan 6Dec 25
16°F–––––––––

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°FNov 1Nov 5Nov 9Nov 13Nov 17Nov 20Nov 25Dec 1Dec 6
32°FNov 9Nov 16Nov 20Nov 25Nov 30Dec 4Dec 8Dec 17Dec 29
28°FNov 20Nov 29Dec 4Dec 12Dec 20Dec 27Jan 2Jan 11Jan 29
24°FDec 4Dec 15Dec 25Jan 1Jan 5Jan 12Jan 21Feb 1Feb 10
20°FDec 18Jan 1Jan 6Jan 9Jan 15Jan 23Feb 1Feb 7Feb 22
16°F–––––––––

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°F279267261254249243236230220
32°F311300292283276269263255245
28°F353340330322314306299289275
24°F365365365361351340331319305
20°F365365365365365365365365346
16°F365365365365365365365365365

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
94% of years
24°F or colder
62% of years
20°F or colder
20% of years
16°F or colder
3% 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
1,379
Cooling degree days, base 65°F
3,026
Growing degree days, base 40°F
10,793
Growing degree days, base 45°F
9,022
Growing degree days, base 50°F
7,318
Growing degree days, base 55°F
5,728
Growing degree days, base 60°F
4,294

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January39013167
February26119213
March14167400
April40145556
May2348811
June0514964
July05971,062
August05901,055
September1440889
October36215647
November17258355
December33619202

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 1.5 km from Sealy. 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 USC00418160 (Sealy). Public domain.