Las Vegas climate

Las Vegas Frost Dates and Growing Season

NOAA 1991-2020 normals for Las Vegas Wwtp, 3.1 km from Las Vegas, elevation 6349 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Las Vegas Wwtp. 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 May 24 and the first fall freeze around September 30, a growing season of about 129 days.

Median at 36°F
last June 3, first September 22
Median at 32°F
last May 24, first September 30
Median at 28°F
last May 10, first October 7

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°FJun 18Jun 11Jun 8Jun 5Jun 3Jun 1May 31May 27May 22
32°FJun 6Jun 1May 30May 27May 24May 20May 17May 14May 9
28°FMay 24May 19May 16May 13May 10May 8May 5May 2Apr 29
24°FMay 15May 10May 5May 2Apr 30Apr 28Apr 24Apr 19Apr 13
20°FMay 3Apr 29Apr 24Apr 19Apr 14Apr 10Apr 6Apr 3Mar 31
16°FApr 19Apr 9Apr 5Apr 2Mar 31Mar 27Mar 22Mar 17Mar 10

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°FSep 10Sep 15Sep 18Sep 20Sep 22Sep 23Sep 26Sep 28Oct 1
32°FSep 20Sep 23Sep 26Sep 28Sep 30Oct 2Oct 4Oct 6Oct 11
28°FSep 28Oct 1Oct 3Oct 5Oct 7Oct 10Oct 13Oct 16Oct 20
24°FOct 3Oct 7Oct 10Oct 14Oct 17Oct 19Oct 22Oct 27Nov 1
20°FOct 10Oct 16Oct 20Oct 23Oct 27Oct 29Nov 1Nov 4Nov 9
16°FOct 19Oct 25Oct 29Nov 1Nov 3Nov 6Nov 10Nov 14Nov 19

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°F1231191161121091051029790
32°F146140136132129126123118113
28°F167161157153150147143139133
24°F191183177173170166161156150
20°F216208202197192187182177170
16°F240233227222216212207201192

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
100% 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
6,093
Cooling degree days, base 65°F
264
Growing degree days, base 40°F
4,296
Growing degree days, base 45°F
3,139
Growing degree days, base 50°F
2,162
Growing degree days, base 55°F
1,363
Growing degree days, base 60°F
733

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,06300
February87901
March76408
April519045
May3034184
June5957449
July9108564
August1583533
September15213313
October487062
November78504
December1,05900

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 3.1 km from Las Vegas. 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 USC00294862 (Las Vegas Wwtp). Public domain.