Jourdanton climate

Jourdanton Frost Dates and Growing Season

NOAA 1991-2020 normals for Pleasanton, 8.2 km from Jourdanton, elevation 358 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Pleasanton. 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 February 27 and the first fall freeze around November 28, a growing season of about 274 days.

Median at 36°F
last March 12, first November 14
Median at 32°F
last February 27, first November 28
Median at 28°F
last February 10, first December 10

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°FApr 5Mar 30Mar 22Mar 17Mar 12Mar 7Mar 3Feb 27Feb 21
32°FMar 20Mar 12Mar 6Mar 2Feb 27Feb 22Feb 15Feb 7Jan 28
28°FMar 8Mar 1Feb 24Feb 16Feb 10Feb 2Jan 26Jan 19Jan 3
24°FFeb 28Feb 16Feb 6Jan 30Jan 22Jan 17Jan 7Dec 31Dec 19
20°FFeb 8Jan 28Jan 20Jan 15Jan 8Jan 4Dec 30Dec 21Dec 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 30Nov 3Nov 6Nov 10Nov 14Nov 18Nov 23Nov 29Dec 5
32°FNov 7Nov 14Nov 19Nov 23Nov 28Dec 1Dec 6Dec 12Dec 28
28°FNov 17Nov 25Dec 1Dec 5Dec 10Dec 19Dec 27Jan 4Jan 12
24°FNov 30Dec 7Dec 15Dec 23Dec 29Jan 3Jan 8Jan 19Feb 5
20°FDec 7Dec 17Dec 24Dec 30Jan 2Jan 7Jan 14Jan 21Feb 2
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°F279268260253246241234227217
32°F312299290281274269262253244
28°F348336327317308301291281267
24°F365365365356346339332319304
20°F365365365365365365365355342
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
96% of years
24°F or colder
73% of years
20°F or colder
31% of years
16°F or colder
9% 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
1,372
Cooling degree days, base 65°F
3,331
Growing degree days, base 40°F
11,105
Growing degree days, base 45°F
9,329
Growing degree days, base 50°F
7,629
Growing degree days, base 55°F
6,049
Growing degree days, base 60°F
4,612

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January39710152
February25926224
March12988435
April29192613
May3398860
June05521,002
July06311,096
August06421,107
September1466915
October31241676
November16969365
December35418185

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 8.2 km from Jourdanton. Low ground, valleys and open fields freeze earlier and later than a town center or a hillside.

More

Sources

NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal normals for station USC00417111 (Pleasanton). Public domain.