Riverbend climate

Riverbend Frost Dates and Growing Season

NOAA 1991-2020 normals for Cedar Lake, 5.9 km from Riverbend, elevation 1560 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Cedar Lake. 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 23 and the first fall freeze around November 1, a growing season of about 193 days.

Median at 36°F
last May 10, first October 16
Median at 32°F
last April 23, first November 1
Median at 28°F
last March 24, first November 22

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 27May 21May 17May 15May 10May 7May 3Apr 30Apr 25
32°FMay 13May 6May 2Apr 28Apr 23Apr 18Apr 14Apr 9Apr 3
28°FApr 21Apr 10Apr 2Mar 29Mar 24Mar 19Mar 13Mar 6Feb 27
24°FMar 20Mar 11Mar 2Feb 26Feb 20Feb 14Feb 5Jan 22Jan 8
20°FFeb 26Feb 19Feb 12Feb 4Jan 26Jan 14Jan 5Dec 23Dec 9
16°FFeb 21Feb 14Feb 5Jan 29Jan 12Jan 1Dec 22Dec 11Dec 2

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 1Oct 5Oct 8Oct 13Oct 16Oct 18Oct 21Oct 25Oct 31
32°FOct 17Oct 23Oct 27Oct 30Nov 1Nov 6Nov 10Nov 15Nov 22
28°FNov 2Nov 9Nov 13Nov 17Nov 22Nov 26Dec 1Dec 7Dec 15
24°FNov 19Nov 25Dec 1Dec 5Dec 10Dec 17Dec 25Jan 1Jan 17
20°FNov 25Dec 1Dec 8Dec 15Dec 21Jan 1Jan 10Jan 26Feb 11
16°FNov 27Dec 5Dec 10Dec 18Dec 29Jan 7Jan 23Feb 6Feb 18

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°F177170164160156152147142134
32°F222210204198193188183177169
28°F277266256249243235229220208
24°F348330319309299290282272259
20°F365365362351340330322313300
16°F365365365365365365351336322

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
98% of years
20°F or colder
75% of years
16°F or colder
43% 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
6,723
Cooling degree days, base 65°F
59
Growing degree days, base 40°F
3,091
Growing degree days, base 45°F
1,998
Growing degree days, base 50°F
1,171
Growing degree days, base 55°F
584
Growing degree days, base 60°F
225

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January91500
February79000
March79203
April641019
May454191
June3135158
July16424326
August14222346
September2815185
October544040
November75602
December93300

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 5.9 km from Riverbend. 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 USC00451233 (Cedar Lake). Public domain.