Ramsey County climate

Ramsey County Frost Dates and Growing Season

NOAA 1991-2020 normals for Devils Lake Kdlr, 21.1 km from Ramsey County, elevation 1464 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Devils Lake Kdlr. 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 6 and the first fall freeze around October 5, a growing season of about 152 days.

Median at 36°F
last May 15, first September 28
Median at 32°F
last May 6, first October 5
Median at 28°F
last April 27, first October 14

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 28May 23May 20May 17May 15May 13May 10May 6May 3
32°FMay 19May 15May 11May 8May 6May 3May 1Apr 28Apr 23
28°FMay 10May 6May 2Apr 30Apr 27Apr 24Apr 20Apr 17Apr 13
24°FMay 1Apr 27Apr 23Apr 20Apr 16Apr 14Apr 11Apr 8Apr 4
20°FApr 22Apr 17Apr 14Apr 11Apr 8Apr 6Apr 4Apr 2Mar 29
16°FApr 15Apr 10Apr 7Apr 4Apr 3Apr 1Mar 29Mar 25Mar 20

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 23Sep 25Sep 28Sep 30Oct 1Oct 4Oct 8
32°FSep 26Sep 29Oct 1Oct 3Oct 5Oct 8Oct 10Oct 14Oct 18
28°FOct 3Oct 6Oct 9Oct 12Oct 14Oct 17Oct 19Oct 22Oct 26
24°FOct 9Oct 13Oct 17Oct 20Oct 23Oct 25Oct 28Oct 31Nov 4
20°FOct 17Oct 23Oct 26Oct 28Oct 31Nov 1Nov 4Nov 7Nov 11
16°FOct 25Oct 30Nov 1Nov 3Nov 5Nov 7Nov 10Nov 13Nov 17

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°F150145141138135132129125120
32°F169164159155152149145141136
28°F188182178173170166163158153
24°F206201196192188184180175169
20°F221215211208204200197192186
16°F235228224221217213210205199

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
9,428
Cooling degree days, base 65°F
424
Growing degree days, base 40°F
3,898
Growing degree days, base 45°F
2,981
Growing degree days, base 50°F
2,162
Growing degree days, base 55°F
1,452
Growing degree days, base 60°F
864

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,79200
February1,50600
March1,26801
April719033
May33915199
June9379438
July29164600
August38130558
September22234282
October665151
November1,15501
December1,60400

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 21.1 km from Ramsey County. 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 USW00014912 (Devils Lake Kdlr). Public domain.