Planada climate

Planada Frost Dates and Growing Season

NOAA 1991-2020 normals for Merced, 17.5 km from Planada, elevation 154 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Merced. 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 March 3 and the first fall freeze around November 24, a growing season of about 263 days.

Median at 36°F
last April 7, first November 8
Median at 32°F
last March 3, first November 24
Median at 28°F
last February 2, first December 11

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 1Apr 22Apr 17Apr 11Apr 7Apr 2Mar 27Mar 17Mar 6
32°FApr 10Mar 30Mar 19Mar 11Mar 3Feb 27Feb 22Feb 13Feb 2
28°FMar 11Feb 26Feb 17Feb 9Feb 2Jan 27Jan 19Jan 8Dec 28
24°FFeb 11Jan 31Jan 22Jan 15Jan 9Jan 4Dec 30Dec 25Dec 16
20°FJan 23Jan 17Jan 11Jan 6Jan 2Dec 30Dec 24Dec 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 21Oct 29Nov 2Nov 4Nov 8Nov 11Nov 15Nov 19Nov 24
32°FNov 5Nov 11Nov 16Nov 21Nov 24Nov 27Dec 1Dec 5Dec 14
28°FNov 22Nov 29Dec 2Dec 6Dec 11Dec 16Dec 24Jan 1Jan 14
24°FDec 2Dec 8Dec 13Dec 18Dec 24Dec 29Jan 3Jan 10Jan 24
20°FDec 8Dec 16Dec 20Dec 26Dec 30Jan 2Jan 6Jan 13Jan 20
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°F250236229220213208201195185
32°F303290279270263255247239226
28°F356342333325318307299286271
24°F365365365365358349342334324
20°F365365365365365365365364350
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
95% of years
24°F or colder
57% of years
20°F or colder
17% of years
16°F or colder
1% 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
2,695
Cooling degree days, base 65°F
1,467
Growing degree days, base 40°F
7,917
Growing degree days, base 45°F
6,203
Growing degree days, base 50°F
4,678
Growing degree days, base 55°F
3,389
Growing degree days, base 60°F
2,325

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January605015
February423053
March3281157
April19118282
May57112521
June7254698
July0412877
August0371836
September8239681
October10159424
November3711118
December606018

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 17.5 km from Planada. 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 USC00045532 (Merced). Public domain.