Markesan climate

Markesan Frost Dates and Growing Season

NOAA 1991-2020 normals for Markesan, 0.9 km from Markesan, elevation 861 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Markesan. 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 May 8 and the first fall freeze around October 2, a growing season of about 144 days.

Median at 36°F
last May 20, first September 24
Median at 32°F
last May 8, first October 2
Median at 28°F
last April 28, first October 12

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 31May 27May 25May 22May 20May 17May 13May 10May 5
32°FMay 23May 19May 15May 11May 8May 5May 2Apr 30Apr 25
28°FMay 13May 7May 3Apr 30Apr 28Apr 25Apr 22Apr 18Apr 14
24°FApr 30Apr 26Apr 22Apr 19Apr 16Apr 13Apr 10Apr 7Apr 3
20°FApr 19Apr 14Apr 11Apr 7Apr 5Apr 3Apr 1Mar 28Mar 21
16°FApr 11Apr 5Apr 2Mar 31Mar 28Mar 24Mar 21Mar 17Mar 11

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 10Sep 15Sep 19Sep 21Sep 24Sep 27Sep 29Oct 2Oct 6
32°FSep 19Sep 24Sep 27Sep 30Oct 2Oct 4Oct 7Oct 10Oct 15
28°FSep 28Oct 3Oct 7Oct 10Oct 12Oct 15Oct 18Oct 22Oct 26
24°FOct 10Oct 15Oct 19Oct 22Oct 25Oct 27Oct 30Nov 1Nov 6
20°FOct 23Oct 28Oct 31Nov 1Nov 4Nov 6Nov 10Nov 14Nov 19
16°FNov 1Nov 4Nov 8Nov 12Nov 15Nov 19Nov 22Nov 27Dec 2

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°F144138134130126123119114109
32°F165158152148144141137133127
28°F187179174170165161157152145
24°F209203198194190186182175168
20°F234227222218213209205200194
16°F256247242237232228222218211

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
7,683
Cooling degree days, base 65°F
480
Growing degree days, base 40°F
4,306
Growing degree days, base 45°F
3,288
Growing degree days, base 50°F
2,396
Growing degree days, base 55°F
1,628
Growing degree days, base 60°F
982

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,47700
February1,26000
March1,034013
April623144
May28625238
June55100495
July17179627
August32127559
September18244324
October526488
November90208
December1,29000

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 0.9 km from Markesan. 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 USC00475096 (Markesan). Public domain.