Carson City climate

Carson City Frost Dates and Growing Season

NOAA 1991-2020 normals for Carson City, 4.3 km from Carson City, elevation 4761 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Carson City. 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 4 and the first fall freeze around October 6, a growing season of about 152 days.

Median at 36°F
last May 26, first September 26
Median at 32°F
last May 4, first October 6
Median at 28°F
last April 20, first October 18

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 13Jun 5Jun 2May 30May 26May 22May 18May 12May 5
32°FMay 29May 21May 14May 8May 4May 1Apr 28Apr 25Apr 20
28°FMay 9May 1Apr 27Apr 23Apr 20Apr 18Apr 14Apr 11Apr 6
24°FApr 23Apr 17Apr 11Apr 8Apr 4Apr 1Mar 28Mar 21Mar 11
20°FApr 4Mar 28Mar 21Mar 15Mar 10Mar 6Mar 2Feb 24Feb 16
16°FMar 14Mar 5Mar 1Feb 24Feb 18Feb 13Feb 6Jan 31Jan 19

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 11Sep 16Sep 20Sep 23Sep 26Sep 28Oct 1Oct 4Oct 8
32°FSep 24Sep 28Oct 1Oct 3Oct 6Oct 9Oct 12Oct 15Oct 20
28°FOct 4Oct 8Oct 11Oct 15Oct 18Oct 21Oct 24Oct 27Nov 1
24°FOct 14Oct 19Oct 23Oct 26Oct 29Nov 1Nov 3Nov 8Nov 12
20°FOct 26Oct 31Nov 3Nov 5Nov 9Nov 12Nov 15Nov 20Nov 25
16°FNov 4Nov 9Nov 13Nov 17Nov 21Nov 24Nov 27Dec 1Dec 9

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°F14513713212712311811410899
32°F173166161157152148143135127
28°F201194189184179175170165157
24°F235225218213208203198192183
20°F271261254248242237231224214
16°F311299291284278271264258247

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
5,353
Cooling degree days, base 65°F
538
Growing degree days, base 40°F
4,947
Growing degree days, base 45°F
3,675
Growing degree days, base 50°F
2,618
Growing degree days, base 55°F
1,761
Growing degree days, base 60°F
1,074

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January93601
February74802
March654017
April488068
May27011229
June8081453
July6228687
August11171625
September10146397
October4002126
November706013
December95302

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 4.3 km from Carson City. 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 USC00261485 (Carson City). Public domain.