Laughlin Frost Dates and Growing Season

NOAA 1991-2020 normals for Laughlin, 0.7 km from Laughlin, elevation 605 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Laughlin. 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 5 and the first fall freeze around December 24, a growing season of about 354 days.

Median at 36°F: last February 2, first December 13
Median at 32°F: last January 5, first December 24
Median at 28°F: last January 1, 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 3	Feb 23	Feb 16	Feb 9	Feb 2	Jan 27	Jan 18	Jan 8	Dec 31
32°F	Feb 13	Feb 2	Jan 22	Jan 11	Jan 5	Dec 31	Dec 26	Dec 18	Dec 11
28°F	Feb 10	Feb 1	Jan 16	Jan 4	Jan 1	Dec 28	Dec 23	Dec 18	Dec 11
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 24	Nov 30	Dec 3	Dec 8	Dec 13	Dec 17	Dec 22	Dec 28	Jan 5
32°F	Dec 3	Dec 9	Dec 14	Dec 19	Dec 24	Dec 30	Jan 3	Jan 12	Feb 1
28°F	Dec 10	Dec 15	Dec 21	Dec 24	Dec 31	Jan 3	Jan 12	Jan 31	Feb 10
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	346	336	328	319	311	304	297	288	276
32°F	365	365	365	362	354	346	340	331	317
28°F	365	365	365	365	365	365	365	365	356
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: 61% of years
28°F or colder: 15% of years
24°F or colder: 0% 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: 1,136
Cooling degree days, base 65°F: 4,478
Growing degree days, base 40°F: 12,468
Growing degree days, base 45°F: 10,649
Growing degree days, base 50°F: 8,869
Growing degree days, base 55°F: 7,209
Growing degree days, base 60°F: 5,743

Growing degree days by month, base 50°F

Heating and cooling by month

Month	Heating DD	Cooling DD	Growing DD 50
January	325	1	159
February	206	7	229
March	93	71	444
April	21	217	647
May	2	493	956
June	0	753	1,203
July	0	956	1,421
August	0	925	1,390
September	0	686	1,136
October	9	319	775
November	128	49	373
December	352	1	136

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 0.7 km from Laughlin. 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 USC00264480 (Laughlin). Public domain.