Oak Grove climate

Oak Grove Frost Dates and Growing Season

NOAA 1991-2020 normals for Moline Quad City Intl AP, 7.2 km from Oak Grove, elevation 592 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Moline Quad City Intl AP. 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 24 and the first fall freeze around October 18, a growing season of about 176 days.

Median at 36°F
last May 4, first October 7
Median at 32°F
last April 24, first October 18
Median at 28°F
last April 12, first October 27

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 19May 14May 10May 7May 4May 1Apr 29Apr 25Apr 20
32°FMay 9May 4Apr 30Apr 27Apr 24Apr 21Apr 18Apr 14Apr 9
28°FApr 30Apr 23Apr 18Apr 15Apr 12Apr 9Apr 6Apr 3Mar 30
24°FApr 16Apr 9Apr 6Apr 3Apr 1Mar 30Mar 26Mar 20Mar 15
20°FApr 3Mar 31Mar 28Mar 24Mar 21Mar 17Mar 14Mar 9Mar 4
16°FMar 27Mar 22Mar 18Mar 15Mar 12Mar 8Mar 5Mar 1Feb 25

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 24Sep 29Oct 1Oct 5Oct 7Oct 10Oct 13Oct 15Oct 20
32°FOct 4Oct 9Oct 13Oct 16Oct 18Oct 20Oct 22Oct 25Oct 28
28°FOct 15Oct 20Oct 23Oct 25Oct 27Oct 29Oct 31Nov 3Nov 7
24°FOct 25Oct 30Nov 1Nov 3Nov 6Nov 8Nov 12Nov 16Nov 22
20°FNov 3Nov 7Nov 10Nov 14Nov 17Nov 21Nov 24Nov 28Dec 3
16°FNov 9Nov 16Nov 20Nov 23Nov 26Nov 29Dec 1Dec 5Dec 12

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°F175169164160156153149144137
32°F195189184180176172168163155
28°F217210205201197193189184177
24°F243234229224220216212207199
20°F263256250245241236232227219
16°F282274268263258254250245237

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
6,024
Cooling degree days, base 65°F
1,041
Growing degree days, base 40°F
5,678
Growing degree days, base 45°F
4,502
Growing degree days, base 50°F
3,449
Growing degree days, base 55°F
2,520
Growing degree days, base 60°F
1,716

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,29200
February1,04403
March785237
April41711136
May15376394
June16228661
July2327790
August4265725
September84116484
October36817185
November740132
December1,11903

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 7.2 km from Oak Grove. 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 USW00014923 (Moline Quad City Intl AP). Public domain.