Sinton climate

Sinton Frost Dates and Growing Season

NOAA 1991-2020 normals for Sinton, 3.4 km from Sinton, elevation 48 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Sinton. 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 1 and the first fall freeze around December 17, a growing season of about 324 days.

Median at 36°F
last February 25, first December 1
Median at 32°F
last February 1, first December 17
Median at 28°F
last January 12, first January 1

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°FMar 16Mar 9Mar 5Mar 1Feb 25Feb 18Feb 11Feb 1Jan 22
32°FMar 6Feb 28Feb 18Feb 9Feb 1Jan 26Jan 18Jan 7Dec 27
28°FFeb 24Feb 7Jan 31Jan 22Jan 12Jan 7Jan 1Dec 25Dec 14
24°FFeb 13Jan 30Jan 11Jan 7Jan 3Jan 1Dec 28Dec 20Dec 12
20°F–––––––––
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 10Nov 16Nov 21Nov 27Dec 1Dec 4Dec 9Dec 17Dec 28
32°FNov 22Nov 30Dec 4Dec 9Dec 17Dec 24Dec 30Jan 5Jan 17
28°FDec 3Dec 11Dec 18Dec 26Jan 1Jan 4Jan 9Jan 18Feb 2
24°FDec 10Dec 17Dec 24Dec 29Jan 1Jan 4Jan 7Jan 15Feb 6
20°F–––––––––
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°F322307298290284278271264254
32°F361349339331324315306297282
28°F365365365365361354345335319
24°F365365365365365365365365356
20°F365365365365365365365365365
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
93% of years
28°F or colder
58% of years
24°F or colder
19% of years
20°F or colder
3% of years
16°F or colder
0% 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
1,011
Cooling degree days, base 65°F
3,419
Growing degree days, base 40°F
11,545
Growing degree days, base 45°F
9,749
Growing degree days, base 50°F
7,999
Growing degree days, base 55°F
6,335
Growing degree days, base 60°F
4,799

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January31020224
February18540293
March89103484
April21207636
May1392856
June0531981
July06011,066
August06281,093
September0476926
October17287735
November115100443
December27235263

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 3.4 km from Sinton. 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 USC00418354 (Sinton). Public domain.