Delano climate

Delano Frost Dates and Growing Season

NOAA 1991-2020 normals for Delano, 1.1 km from Delano, elevation 975 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Delano. 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 30 and the first fall freeze around October 8, a growing season of about 159 days.

Median at 36°F
last May 9, first September 28
Median at 32°F
last April 30, first October 8
Median at 28°F
last April 22, first October 19

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 25May 20May 16May 12May 9May 7May 4May 1Apr 28
32°FMay 14May 9May 5May 2Apr 30Apr 29Apr 26Apr 23Apr 18
28°FMay 3Apr 30Apr 27Apr 25Apr 22Apr 19Apr 16Apr 12Apr 6
24°FApr 26Apr 21Apr 17Apr 14Apr 11Apr 8Apr 5Apr 2Mar 29
20°FApr 18Apr 13Apr 9Apr 6Apr 3Apr 1Mar 30Mar 26Mar 20
16°FApr 10Apr 6Apr 3Mar 31Mar 29Mar 25Mar 21Mar 17Mar 12

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 15Sep 20Sep 23Sep 26Sep 28Oct 1Oct 4Oct 6Oct 10
32°FSep 24Sep 29Oct 2Oct 5Oct 8Oct 11Oct 14Oct 17Oct 21
28°FOct 4Oct 10Oct 14Oct 17Oct 19Oct 22Oct 26Oct 28Nov 1
24°FOct 17Oct 21Oct 25Oct 28Oct 30Nov 1Nov 3Nov 7Nov 12
20°FOct 27Oct 31Nov 1Nov 4Nov 7Nov 10Nov 13Nov 16Nov 23
16°FNov 1Nov 5Nov 9Nov 12Nov 15Nov 17Nov 20Nov 24Dec 1

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°F160154149145141137133128122
32°F180172166163159156151147140
28°F202195189185181177173169161
24°F220214209204200197193188182
20°F238229225220216213209205198
16°F252244240236232228223218212

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
8,051
Cooling degree days, base 65°F
612
Growing degree days, base 40°F
4,492
Growing degree days, base 45°F
3,489
Growing degree days, base 50°F
2,592
Growing degree days, base 55°F
1,808
Growing degree days, base 60°F
1,146

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,59600
February1,34000
March1,08207
April619155
May26229261
June48126529
July7235693
August20163608
September16854347
October540486
November97107
December1,39800

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 1.1 km from Delano. 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 USC00212088 (Delano). Public domain.