Mounds View climate

Mounds View Frost Dates and Growing Season

NOAA 1991-2020 normals for U Of Mn St Paul, 13 km from Mounds View, elevation 970 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for U Of Mn St Paul. 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 28 and the first fall freeze around October 8, a growing season of about 162 days.

Median at 36°F
last May 7, first September 30
Median at 32°F
last April 28, first October 8
Median at 28°F
last April 18, 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 24May 18May 13May 10May 7May 5May 2Apr 29Apr 25
32°FMay 14May 7May 4Apr 30Apr 28Apr 25Apr 22Apr 18Apr 14
28°FMay 1Apr 27Apr 23Apr 21Apr 18Apr 15Apr 12Apr 8Apr 4
24°FApr 22Apr 17Apr 13Apr 10Apr 8Apr 5Apr 3Mar 31Mar 26
20°FApr 13Apr 8Apr 5Apr 3Apr 1Mar 30Mar 27Mar 23Mar 17
16°FApr 7Apr 3Mar 31Mar 28Mar 25Mar 22Mar 18Mar 14Mar 9

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 22Sep 26Sep 28Sep 30Oct 2Oct 5Oct 8Oct 14
32°FSep 25Sep 29Oct 2Oct 5Oct 8Oct 11Oct 15Oct 19Oct 22
28°FOct 3Oct 9Oct 14Oct 18Oct 21Oct 23Oct 26Oct 29Nov 4
24°FOct 17Oct 22Oct 26Oct 29Nov 1Nov 2Nov 5Nov 8Nov 13
20°FOct 27Nov 1Nov 3Nov 6Nov 8Nov 11Nov 14Nov 17Nov 23
16°FNov 2Nov 6Nov 9Nov 12Nov 15Nov 18Nov 22Nov 25Nov 30

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°F162155151147144140136131124
32°F183175170165162158154148142
28°F204197193188184179175170163
24°F223216211208204201197193185
20°F241235229225220216212208201
16°F257249245240236232228222216

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
7,992
Cooling degree days, base 65°F
641
Growing degree days, base 40°F
4,566
Growing degree days, base 45°F
3,555
Growing degree days, base 50°F
2,650
Growing degree days, base 55°F
1,856
Growing degree days, base 60°F
1,182

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,60100
February1,31700
March1,05909
April599367
May26234268
June51136536
July9229685
August22170614
September15962364
October530699
November97109
December1,41200

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 13 km from Mounds View. 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 USC00218450 (U Of Mn St Paul). Public domain.