Brinkley climate

Brinkley Frost Dates and Growing Season

NOAA 1991-2020 normals for Brinkley, 2 km from Brinkley, elevation 185 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Brinkley. 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 18 and the first fall freeze around November 11, a growing season of about 237 days.

Median at 36°F
last April 1, first November 1
Median at 32°F
last March 18, first November 11
Median at 28°F
last March 6, first November 25

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 16Apr 11Apr 7Apr 4Apr 1Mar 29Mar 25Mar 20Mar 14
32°FApr 6Mar 31Mar 27Mar 23Mar 18Mar 15Mar 11Mar 7Mar 1
28°FMar 25Mar 17Mar 13Mar 10Mar 6Mar 3Feb 28Feb 23Feb 16
24°FMar 13Mar 7Mar 2Feb 28Feb 23Feb 19Feb 14Feb 7Jan 29
20°FMar 3Feb 25Feb 19Feb 13Feb 6Feb 1Jan 28Jan 21Jan 11
16°FFeb 21Feb 9Feb 3Jan 31Jan 27Jan 21Jan 13Jan 7Dec 28

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 18Oct 22Oct 26Oct 29Nov 1Nov 2Nov 5Nov 9Nov 15
32°FOct 28Nov 1Nov 5Nov 8Nov 11Nov 15Nov 19Nov 24Dec 1
28°FNov 7Nov 12Nov 17Nov 21Nov 25Nov 30Dec 3Dec 9Dec 19
24°FNov 17Nov 26Dec 1Dec 5Dec 11Dec 17Dec 23Dec 30Jan 6
20°FDec 1Dec 11Dec 19Dec 25Dec 30Jan 3Jan 9Jan 15Jan 27
16°FDec 12Dec 23Dec 30Jan 2Jan 7Jan 12Jan 17Jan 25Feb 2

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°F234226222216212208204199193
32°F261254248243237232226220213
28°F289279272266261256251244235
24°F323309302295290283277269259
20°F356343334326320312305299288
16°F365365364355346339333324312

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
96% of years
16°F or colder
72% 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
3,358
Cooling degree days, base 65°F
1,933
Growing degree days, base 40°F
8,012
Growing degree days, base 45°F
6,501
Growing degree days, base 50°F
5,140
Growing degree days, base 55°F
3,923
Growing degree days, base 60°F
2,854

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January800120
February611142
March4309145
April17750337
May33186619
June1393843
July0498963
August0465930
September13260697
October15264387
November4407122
December701136

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 km from Brinkley. 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 USC00030936 (Brinkley). Public domain.