Grandview climate

Grandview Frost Dates and Growing Season

NOAA 1991-2020 normals for Columbus Junction, 14.2 km from Grandview, elevation 590 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Columbus Junction. 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 26 and the first fall freeze around October 10, a growing season of about 167 days.

Median at 36°F
last May 5, first October 1
Median at 32°F
last April 26, first October 10
Median at 28°F
last April 15, first October 21

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 22May 17May 12May 8May 5May 3Apr 30Apr 28Apr 23
32°FMay 11May 5May 2Apr 30Apr 26Apr 23Apr 21Apr 16Apr 11
28°FApr 30Apr 25Apr 22Apr 18Apr 15Apr 12Apr 9Apr 6Apr 2
24°FApr 21Apr 15Apr 11Apr 8Apr 5Apr 3Apr 1Mar 29Mar 23
20°FApr 11Apr 6Apr 3Mar 31Mar 28Mar 25Mar 21Mar 17Mar 12
16°FApr 3Mar 29Mar 25Mar 21Mar 18Mar 15Mar 13Mar 9Mar 4

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 18Sep 21Sep 25Sep 28Oct 1Oct 3Oct 7Oct 10Oct 13
32°FSep 23Sep 29Oct 3Oct 7Oct 10Oct 13Oct 16Oct 19Oct 22
28°FOct 2Oct 9Oct 13Oct 17Oct 21Oct 23Oct 25Oct 29Nov 1
24°FOct 16Oct 21Oct 24Oct 28Oct 30Nov 1Nov 3Nov 7Nov 12
20°FOct 27Nov 1Nov 2Nov 5Nov 7Nov 10Nov 13Nov 17Nov 22
16°FNov 4Nov 8Nov 11Nov 14Nov 17Nov 19Nov 23Nov 26Dec 1

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°F167162157153149144140136129
32°F186179175170167162158153146
28°F206199196192188183179173167
24°F226219214211207203199194187
20°F245238233230225221217212206
16°F264258253248244239235230223

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
6,661
Cooling degree days, base 65°F
790
Growing degree days, base 40°F
5,163
Growing degree days, base 45°F
4,055
Growing degree days, base 50°F
3,051
Growing degree days, base 55°F
2,166
Growing degree days, base 60°F
1,411

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,38200
February1,14401
March871023
April4667115
May18748338
June30169589
July3263725
August9212668
September11582422
October4319146
November821023
December1,20302

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 14.2 km from Grandview. 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 USC00131731 (Columbus Junction). Public domain.