Weldon climate

Weldon Frost Dates and Growing Season

NOAA 1991-2020 normals for Kern River Ph 3, 18.7 km from Weldon, elevation 2703 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Kern River Ph 3. 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 7 and the first fall freeze around November 11, a growing season of about 217 days.

Median at 36°F
last April 26, first October 31
Median at 32°F
last April 7, first November 11
Median at 28°F
last March 10, first November 24

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 16May 9May 3Apr 30Apr 26Apr 23Apr 18Apr 14Apr 8
32°FApr 28Apr 19Apr 14Apr 10Apr 7Apr 4Apr 1Mar 25Mar 16
28°FApr 6Mar 30Mar 22Mar 16Mar 10Mar 5Feb 28Feb 22Feb 10
24°FMar 4Feb 26Feb 16Feb 9Feb 3Jan 29Jan 20Jan 6Dec 27
20°FFeb 3Jan 27Jan 18Jan 11Jan 5Dec 31Dec 26Dec 20Dec 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 17Oct 22Oct 25Oct 29Oct 31Nov 2Nov 5Nov 8Nov 11
32°FOct 30Nov 2Nov 5Nov 9Nov 11Nov 14Nov 17Nov 20Nov 26
28°FNov 10Nov 14Nov 18Nov 21Nov 24Nov 28Dec 1Dec 5Dec 12
24°FNov 22Nov 27Dec 1Dec 5Dec 9Dec 13Dec 21Jan 1Jan 11
20°FDec 1Dec 9Dec 13Dec 21Dec 27Jan 1Jan 5Jan 14Jan 26
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°F207200196191186182177171161
32°F241233227222217213209202193
28°F291278270264257250242236226
24°F356338330322314305295283269
20°F365365365365365356348339331
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
95% of years
20°F or colder
48% of years
16°F or colder
6% 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
2,986
Cooling degree days, base 65°F
1,654
Growing degree days, base 40°F
7,831
Growing degree days, base 45°F
6,151
Growing degree days, base 50°F
4,694
Growing degree days, base 55°F
3,483
Growing degree days, base 60°F
2,477

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January587025
February475047
March4151117
April27312215
May11587440
June13265702
July0483948
August0457922
September10274714
October11870419
November3854119
December595025

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 18.7 km from Weldon. 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 USC00044523 (Kern River Ph 3). Public domain.