Park Rapids climate

Park Rapids Frost Dates and Growing Season

NOAA 1991-2020 normals for Park Rapids Muni AP, 2.5 km from Park Rapids, elevation 1434 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Park Rapids Muni 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 May 14 and the first fall freeze around September 25, a growing season of about 133 days.

Median at 36°F
last May 25, first September 16
Median at 32°F
last May 14, first September 25
Median at 28°F
last May 4, first October 4

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 7Jun 2May 30May 27May 25May 22May 19May 15May 11
32°FMay 27May 22May 18May 16May 14May 11May 8May 5May 1
28°FMay 17May 13May 9May 7May 4May 2Apr 30Apr 27Apr 23
24°FMay 9May 4May 1Apr 29Apr 27Apr 24Apr 21Apr 17Apr 12
20°FMay 1Apr 27Apr 23Apr 21Apr 17Apr 14Apr 11Apr 7Apr 3
16°FApr 22Apr 18Apr 14Apr 11Apr 7Apr 5Apr 2Mar 31Mar 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 1Sep 6Sep 10Sep 14Sep 16Sep 19Sep 21Sep 25Sep 28
32°FSep 12Sep 17Sep 20Sep 23Sep 25Sep 28Sep 30Oct 3Oct 8
28°FSep 20Sep 26Sep 29Oct 1Oct 4Oct 6Oct 10Oct 13Oct 19
24°FOct 1Oct 5Oct 8Oct 11Oct 15Oct 17Oct 21Oct 24Oct 28
20°FOct 10Oct 15Oct 20Oct 23Oct 26Oct 29Nov 1Nov 4Nov 9
16°FOct 20Oct 26Oct 30Nov 1Nov 4Nov 6Nov 9Nov 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°F13112612111711411010510094
32°F150144140136133129125120115
28°F170164158155151148143139132
24°F190183178174170165162157150
20°F210204199195190186181176169
16°F227220216212209204200195188

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
9,305
Cooling degree days, base 65°F
367
Growing degree days, base 40°F
3,787
Growing degree days, base 45°F
2,865
Growing degree days, base 50°F
2,052
Growing degree days, base 55°F
1,358
Growing degree days, base 60°F
787

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,77800
February1,47600
March1,20103
April722030
May35015187
June9472429
July30143578
August53106518
September24729259
October666147
November1,11502
December1,57300

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 2.5 km from Park Rapids. 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 USW00094967 (Park Rapids Muni AP). Public domain.