Hydro climate

Hydro Frost Dates and Growing Season

NOAA 1991-2020 normals for Weatherford, 11.4 km from Hydro, elevation 1618 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Weatherford. 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 3 and the first fall freeze around November 3, a growing season of about 214 days.

Median at 36°F
last April 15, first October 24
Median at 32°F
last April 3, first November 3
Median at 28°F
last March 21, first November 11

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 1Apr 26Apr 22Apr 19Apr 15Apr 11Apr 7Apr 3Mar 31
32°FApr 21Apr 16Apr 10Apr 6Apr 3Apr 1Mar 28Mar 23Mar 16
28°FApr 7Apr 2Mar 30Mar 25Mar 21Mar 15Mar 11Mar 7Mar 2
24°FMar 30Mar 21Mar 14Mar 11Mar 7Mar 4Mar 1Feb 26Feb 20
20°FMar 14Mar 9Mar 4Mar 1Feb 26Feb 22Feb 18Feb 11Jan 31
16°FMar 5Mar 1Feb 23Feb 18Feb 12Feb 6Jan 31Jan 25Jan 15

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 13Oct 17Oct 20Oct 22Oct 24Oct 27Oct 30Nov 2Nov 6
32°FOct 20Oct 24Oct 28Nov 1Nov 3Nov 6Nov 9Nov 12Nov 18
28°FOct 26Nov 1Nov 5Nov 8Nov 11Nov 14Nov 18Nov 22Nov 28
24°FNov 2Nov 8Nov 13Nov 18Nov 22Nov 26Nov 30Dec 4Dec 9
20°FNov 12Nov 18Nov 24Nov 29Dec 3Dec 6Dec 11Dec 16Dec 23
16°FNov 24Dec 1Dec 5Dec 11Dec 15Dec 20Dec 27Jan 3Jan 13

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°F214207202198193189184179172
32°F236229224218214209204198190
28°F259250245240235230225219209
24°F284275269263257252247240231
20°F309300292286281275269262253
16°F338328318310304298293286276

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
99% 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
3,715
Cooling degree days, base 65°F
1,937
Growing degree days, base 40°F
7,810
Growing degree days, base 45°F
6,340
Growing degree days, base 50°F
5,020
Growing degree days, base 55°F
3,844
Growing degree days, base 60°F
2,818

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January857011
February653134
March4547138
April21238301
May48158576
June2380828
July05411,006
August1484948
September20268698
October17556363
November4854103
December807014

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 11.4 km from Hydro. 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 USC00349422 (Weatherford). Public domain.