Nevada City climate

Nevada City Frost Dates and Growing Season

NOAA 1991-2020 normals for Nevada City, 2.3 km from Nevada City, elevation 2781 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Nevada 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 April 14 and the first fall freeze around November 20, a growing season of about 218 days.

Median at 36°F
last April 30, first November 2
Median at 32°F
last April 14, first November 20
Median at 28°F
last March 17, first December 8

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°FMay 23May 14May 8May 3Apr 30Apr 27Apr 23Apr 19Apr 12
32°FMay 7Apr 29Apr 23Apr 19Apr 14Apr 9Apr 4Mar 28Mar 15
28°FApr 18Apr 9Apr 4Mar 27Mar 17Mar 7Feb 27Feb 13Jan 24
24°FApr 1Feb 28Feb 18Feb 6Jan 24Jan 12Jan 2Dec 27Dec 13
20°FJan 31Jan 18Jan 9Jan 4Jan 1Dec 29Dec 23Dec 18Dec 12
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.

Threshold10%20%30%40%50%60%70%80%90%
36°FOct 10Oct 17Oct 24Oct 29Nov 2Nov 6Nov 10Nov 15Nov 21
32°FOct 23Nov 3Nov 10Nov 16Nov 20Nov 25Nov 30Dec 4Dec 12
28°FNov 12Nov 22Nov 29Dec 3Dec 8Dec 13Dec 19Dec 31Jan 19
24°FNov 27Dec 6Dec 15Dec 20Dec 27Jan 2Jan 13Jan 27Feb 21
20°FDec 9Dec 16Dec 21Dec 26Dec 30Jan 1Jan 6Jan 16Jan 29
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.

Threshold10%20%30%40%50%60%70%80%90%
36°F211202195189184178171164155
32°F253242232224218211205196184
28°F324301287278268259248237222
24°F365365365356346336325305274
20°F365365365365365365365365350
16°F365365365365365365365365365

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
70% of years
20°F or colder
22% of years
16°F or colder
4% 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
4,038
Cooling degree days, base 65°F
847
Growing degree days, base 40°F
6,089
Growing degree days, base 45°F
4,585
Growing degree days, base 50°F
3,339
Growing degree days, base 55°F
2,325
Growing degree days, base 60°F
1,501

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January68209
February588018
March555055
April4162113
May22332293
June68114498
July5267727
August5248708
September46151556
October22032295
November501163
December73002

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 2.3 km from Nevada 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 USC00046136 (Nevada City). Public domain.