Caspian climate

Caspian Frost Dates and Growing Season

NOAA 1991-2020 normals for Stambaugh 2SSE, 1 km from Caspian, elevation 1450 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Stambaugh 2SSE. 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 June 4 and the first fall freeze around September 10, a growing season of about 95 days.

Median at 32°F
last June 4, first September 10
Median at 28°F
last May 23, first September 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°F–––––––––
32°FJun 26Jun 18Jun 12Jun 8Jun 4Jun 1May 30May 26May 22
28°FJun 6Jun 1May 29May 26May 23May 20May 16May 12May 7
24°FMay 26May 21May 17May 13May 10May 7May 3Apr 30Apr 26
20°FMay 14May 8May 3Apr 30Apr 28Apr 25Apr 22Apr 19Apr 14
16°FApr 30Apr 27Apr 23Apr 21Apr 18Apr 16Apr 12Apr 9Apr 5

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°F–––––––––
32°FAug 21Aug 29Sep 3Sep 6Sep 10Sep 13Sep 17Sep 20Sep 25
28°FSep 7Sep 13Sep 18Sep 21Sep 24Sep 28Oct 1Oct 3Oct 8
24°FSep 20Sep 26Sep 30Oct 2Oct 5Oct 9Oct 11Oct 16Oct 21
20°FOct 2Oct 7Oct 11Oct 15Oct 19Oct 22Oct 26Oct 30Nov 2
16°FOct 16Oct 23Oct 27Oct 31Nov 1Nov 4Nov 8Nov 12Nov 16

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°F887770635852464032
32°F1181111051009590847566
28°F145138133127123119114108100
24°F169162157152148145141135127
20°F194186181177172168164158151
16°F216208203199196192186182174

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
9,776
Cooling degree days, base 65°F
151
Growing degree days, base 40°F
3,023
Growing degree days, base 45°F
2,169
Growing degree days, base 50°F
1,442
Growing degree days, base 55°F
851
Growing degree days, base 60°F
417

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,68200
February1,46200
March1,29902
April843013
May4528127
June18133312
July10262426
August14636357
September34113174
October718030
November1,07402
December1,47600

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 km from Caspian. 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 USC00207812 (Stambaugh 2SSE). Public domain.