Larga Vista Frost Dates and Growing Season

NOAA 1991-2020 normals for Laredo AFB, 5.3 km from Larga Vista, elevation 505 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Laredo AFB. 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 20 and the first fall freeze around December 25, a growing season of about 344 days.

Median at 36°F: last February 8, first December 11
Median at 32°F: last January 20, first December 25
Median at 28°F: last January 6, first December 31

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 9	Mar 1	Feb 24	Feb 16	Feb 8	Jan 31	Jan 25	Jan 17	Dec 31
32°F	Feb 26	Feb 14	Feb 4	Jan 28	Jan 20	Jan 10	Jan 4	Dec 27	Dec 16
28°F	Feb 17	Feb 3	Jan 21	Jan 10	Jan 6	Jan 1	Dec 24	Dec 19	Dec 12
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 23	Nov 29	Dec 3	Dec 7	Dec 11	Dec 16	Dec 23	Jan 1	Jan 11
32°F	Dec 2	Dec 9	Dec 15	Dec 19	Dec 25	Jan 1	Jan 6	Jan 16	Feb 3
28°F	Dec 8	Dec 15	Dec 19	Dec 23	Dec 31	Jan 4	Jan 9	Jan 21	Feb 5
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	343	333	323	315	307	299	290	283	271
32°F	365	365	362	352	344	338	330	317	301
28°F	365	365	365	365	365	365	365	354	338
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: 98% of years
32°F or colder: 74% of years
28°F or colder: 30% of years
24°F or colder: 4% of years
20°F or colder: 0% 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: 811
Cooling degree days, base 65°F: 4,341
Growing degree days, base 40°F: 12,658
Growing degree days, base 45°F: 10,849
Growing degree days, base 50°F: 9,074
Growing degree days, base 55°F: 7,374
Growing degree days, base 60°F: 5,791

Growing degree days by month, base 50°F

Heating and cooling by month

Month	Heating DD	Cooling DD	Growing DD 50
January	262	28	260
February	142	72	363
March	61	191	599
April	5	337	783
May	0	529	994
June	0	660	1,110
July	0	716	1,181
August	0	739	1,204
September	0	539	989
October	14	362	814
November	93	132	494
December	235	36	284

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 5.3 km from Larga Vista. 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 USW00012907 (Laredo AFB). Public domain.