Bryan climate

Bryan Frost Dates and Growing Season

NOAA 1991-2020 normals for Bryan 2 Se, 2.5 km from Bryan, elevation 730 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Bryan 2 Se. 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 26 and the first fall freeze around October 17, a growing season of about 170 days.

Median at 36°F
last May 6, first October 5
Median at 32°F
last April 26, first October 17
Median at 28°F
last April 17, first October 28

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 20May 15May 12May 9May 6May 3May 1Apr 28Apr 23
32°FMay 11May 6May 2Apr 29Apr 26Apr 23Apr 21Apr 18Apr 14
28°FApr 30Apr 25Apr 22Apr 19Apr 17Apr 15Apr 12Apr 8Apr 4
24°FApr 19Apr 14Apr 11Apr 7Apr 5Apr 2Mar 31Mar 28Mar 21
20°FApr 9Apr 4Mar 31Mar 29Mar 26Mar 22Mar 18Mar 14Mar 8
16°FMar 31Mar 26Mar 21Mar 17Mar 14Mar 11Mar 7Mar 4Feb 26

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°FSep 22Sep 27Oct 1Oct 3Oct 5Oct 8Oct 11Oct 14Oct 18
32°FOct 3Oct 8Oct 11Oct 14Oct 17Oct 20Oct 23Oct 25Oct 30
28°FOct 16Oct 21Oct 23Oct 26Oct 28Oct 31Nov 1Nov 5Nov 9
24°FOct 26Oct 31Nov 2Nov 5Nov 7Nov 10Nov 13Nov 16Nov 21
20°FNov 5Nov 8Nov 12Nov 15Nov 18Nov 21Nov 26Dec 1Dec 8
16°FNov 11Nov 16Nov 21Nov 25Nov 29Dec 3Dec 8Dec 13Dec 20

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°F169163159155152148144140134
32°F190184179175170167162157150
28°F211205201197193189185181175
24°F238230225220216213209204198
20°F264254248243239235230225217
16°F287279272267261256251245237

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
6,303
Cooling degree days, base 65°F
779
Growing degree days, base 40°F
5,139
Growing degree days, base 45°F
4,012
Growing degree days, base 50°F
3,015
Growing degree days, base 55°F
2,144
Growing degree days, base 60°F
1,394

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,25801
February1,07201
March877121
April506387
May19547331
June25170596
July3268730
August11200654
September10380430
October4049149
November765015
December1,08502

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 2.5 km from Bryan. 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 USC00331042 (Bryan 2 Se). Public domain.