Ricardo climate

Ricardo Frost Dates and Growing Season

NOAA 1991-2020 normals for Kingsville, 12.2 km from Ricardo, elevation 57 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Kingsville. 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 25 and the first fall freeze around December 20, a growing season of about 329 days.

Median at 36°F
last February 17, first December 4
Median at 32°F
last January 25, first December 20
Median at 28°F
last January 9, first January 1

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°FMar 14Mar 7Mar 2Feb 24Feb 17Feb 10Feb 3Jan 26Jan 15
32°FMar 3Feb 21Feb 8Jan 31Jan 25Jan 18Jan 10Jan 2Dec 18
28°FFeb 17Feb 2Jan 25Jan 16Jan 9Jan 3Dec 30Dec 23Dec 12
24°FJan 30Jan 20Jan 11Jan 9Jan 5Jan 1Dec 25Dec 19Dec 11
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.

Threshold10%20%30%40%50%60%70%80%90%
36°FNov 13Nov 19Nov 24Nov 30Dec 4Dec 8Dec 14Dec 24Jan 2
32°FNov 25Dec 2Dec 7Dec 13Dec 20Dec 28Jan 1Jan 8Jan 21
28°FDec 7Dec 15Dec 23Dec 29Jan 1Jan 5Jan 9Jan 17Feb 3
24°FDec 8Dec 16Dec 22Dec 28Jan 1Jan 6Jan 9Jan 15Jan 28
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.

Threshold10%20%30%40%50%60%70%80%90%
36°F328316306298290283275268258
32°F365354343336329320310300289
28°F365365365365365357348340329
24°F365365365365365365365365357
20°F365365365365365365365365365
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
89% of years
28°F or colder
48% of years
24°F or colder
14% of years
20°F or colder
1% 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
835
Cooling degree days, base 65°F
3,882
Growing degree days, base 40°F
12,181
Growing degree days, base 45°F
10,376
Growing degree days, base 50°F
8,610
Growing degree days, base 55°F
6,914
Growing degree days, base 60°F
5,331

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January26937272
February15263345
March73146542
April12276714
May0453918
June05821,032
July06401,105
August06631,128
September0512962
October12326780
November93129491
December22457321

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 12.2 km from Ricardo. 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 USC00414810 (Kingsville). Public domain.