Medora climate

Medora Frost Dates and Growing Season

NOAA 1991-2020 normals for Medora, 0.3 km from Medora, elevation 2268 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Medora. 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 19 and the first fall freeze around September 20, a growing season of about 123 days.

Median at 36°F
last May 29, first September 8
Median at 32°F
last May 19, first September 20
Median at 28°F
last May 8, first September 29

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 13Jun 6Jun 3Jun 1May 29May 27May 24May 21May 18
32°FJun 1May 27May 24May 21May 19May 16May 14May 11May 7
28°FMay 23May 18May 14May 11May 8May 5May 3Apr 30Apr 26
24°FMay 12May 7May 3May 1Apr 28Apr 25Apr 22Apr 18Apr 14
20°FApr 30Apr 26Apr 22Apr 19Apr 16Apr 13Apr 10Apr 6Apr 2
16°FApr 20Apr 15Apr 12Apr 9Apr 6Apr 3Apr 1Mar 28Mar 19

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°FAug 27Aug 31Sep 3Sep 6Sep 8Sep 11Sep 14Sep 17Sep 22
32°FSep 6Sep 10Sep 15Sep 18Sep 20Sep 23Sep 26Sep 29Oct 4
28°FSep 16Sep 20Sep 23Sep 26Sep 29Oct 1Oct 5Oct 8Oct 13
24°FSep 22Sep 26Sep 30Oct 4Oct 8Oct 11Oct 14Oct 17Oct 22
20°FSep 29Oct 6Oct 10Oct 14Oct 17Oct 21Oct 24Oct 28Nov 1
16°FOct 10Oct 16Oct 21Oct 25Oct 28Oct 30Nov 2Nov 5Nov 11

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°F12011511010610299959082
32°F142136131127123119115111104
28°F163156152147143139135130124
24°F181175170166163159154148141
20°F203197192187183179175170163
16°F224216211207203199195189183

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
8,419
Cooling degree days, base 65°F
484
Growing degree days, base 40°F
4,000
Growing degree days, base 45°F
3,039
Growing degree days, base 50°F
2,208
Growing degree days, base 55°F
1,502
Growing degree days, base 60°F
920

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,53400
February1,26600
March1,05305
April676137
May36310176
June11062405
July22200643
August43173596
September23038288
October659255
November1,04303
December1,42300

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 0.3 km from Medora. 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 USC00325813 (Medora). Public domain.