Redby climate

Redby Frost Dates and Growing Season

NOAA 1991-2020 normals for Red Lake Indian Agcy, 7.7 km from Redby, elevation 1216 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Red Lake Indian Agcy. 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 12 and the first fall freeze around October 4, a growing season of about 142 days.

Median at 36°F
last May 23, first September 24
Median at 32°F
last May 12, first October 4
Median at 28°F
last May 2, first October 15

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

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

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°F143137131127123119114109101
32°F164157151147142138133127119
28°F184176172167162158153148139
24°F204198193188183178174168159
20°F220214210206202197193186180
16°F235228224219215211207202196

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
9,639
Cooling degree days, base 65°F
339
Growing degree days, base 40°F
3,629
Growing degree days, base 45°F
2,741
Growing degree days, base 50°F
1,958
Growing degree days, base 55°F
1,287
Growing degree days, base 60°F
740

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,80900
February1,51700
March1,25902
April795021
May39614170
June11560397
July39136563
August56102512
September26724242
October670248
November1,12503
December1,59200

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 7.7 km from Redby. 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 USC00216795 (Red Lake Indian Agcy). Public domain.