Hargill Frost Dates and Growing Season

NOAA 1991-2020 normals for Edinburg 17 Nne, 10.4 km from Hargill, elevation 64 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Edinburg 17 Nne. 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 January 21 and the first fall freeze around December 23, a growing season of about 338 days.

Median at 36°F: last February 8, first December 5
Median at 32°F: last January 21, first December 23
Median at 28°F: last January 4, 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.

Threshold	10%	20%	30%	40%	50%	60%	70%	80%	90%
36°F	Mar 10	Mar 2	Feb 23	Feb 15	Feb 8	Jan 31	Jan 25	Jan 18	Jan 4
32°F	Feb 28	Feb 15	Feb 5	Jan 27	Jan 21	Jan 11	Jan 4	Dec 27	Dec 11
28°F	Feb 12	Jan 31	Jan 18	Jan 9	Jan 4	Dec 31	Dec 25	Dec 17	Dec 10
24°F	–	–	–	–	–	–	–	–	–
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.

Threshold	10%	20%	30%	40%	50%	60%	70%	80%	90%
36°F	Nov 14	Nov 21	Nov 25	Dec 1	Dec 5	Dec 11	Dec 18	Dec 28	Jan 6
32°F	Nov 23	Dec 1	Dec 8	Dec 15	Dec 23	Dec 30	Jan 3	Jan 10	Feb 1
28°F	Dec 6	Dec 13	Dec 20	Dec 28	Jan 1	Jan 5	Jan 9	Jan 19	Feb 4
24°F	–	–	–	–	–	–	–	–	–
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.

Threshold	10%	20%	30%	40%	50%	60%	70%	80%	90%
36°F	341	329	320	310	304	294	286	276	265
32°F	365	365	356	346	338	331	323	311	295
28°F	365	365	365	365	365	365	362	350	335
24°F	365	365	365	365	365	365	365	365	365
20°F	365	365	365	365	365	365	365	365	365
16°F	365	365	365	365	365	365	365	365	365

How often it gets that cold

The share of years with at least one night at or below each temperature.

36°F or colder: 99% of years
32°F or colder: 78% of years
28°F or colder: 35% of years
24°F or colder: 8% of years
20°F or colder: 1% 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: 644
Cooling degree days, base 65°F: 4,270
Growing degree days, base 40°F: 12,755
Growing degree days, base 45°F: 10,943
Growing degree days, base 50°F: 9,155
Growing degree days, base 55°F: 7,421
Growing degree days, base 60°F: 5,785

Growing degree days by month, base 50°F

Heating and cooling by month

Month	Heating DD	Cooling DD	Growing DD 50
January	208	59	340
February	113	109	426
March	46	200	620
April	8	330	773
May	0	513	978
June	0	595	1,046
July	0	664	1,129
August	0	677	1,142
September	0	530	980
October	6	353	812
November	75	162	540
December	188	78	370

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 10.4 km from Hargill. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USW00012987 (Edinburg 17 Nne). Public domain.