Boardman climate

Boardman Frost Dates and Growing Season

NOAA 1991-2020 normals for Boardman, 1 km from Boardman, elevation 280 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Boardman. 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 14 and the first fall freeze around October 21, a growing season of about 188 days.

Median at 36°F
last May 1, first October 8
Median at 32°F
last April 14, first October 21
Median at 28°F
last March 28, first November 1

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 13May 9May 6May 3May 1Apr 28Apr 25Apr 21Apr 15
32°FMay 2Apr 27Apr 23Apr 18Apr 14Apr 11Apr 8Apr 3Mar 28
28°FApr 15Apr 7Apr 3Mar 31Mar 28Mar 23Mar 18Mar 14Mar 9
24°FMar 30Mar 22Mar 16Mar 11Mar 8Mar 4Feb 28Feb 24Feb 17
20°FMar 12Mar 5Mar 1Feb 26Feb 21Feb 16Feb 9Jan 31Jan 12
16°FMar 4Feb 27Feb 21Feb 14Feb 7Jan 31Jan 19Jan 7Dec 22

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 27Oct 1Oct 3Oct 5Oct 8Oct 11Oct 14Oct 17Oct 22
32°FOct 5Oct 10Oct 14Oct 18Oct 21Oct 24Oct 26Oct 30Nov 4
28°FOct 17Oct 22Oct 25Oct 29Nov 1Nov 3Nov 6Nov 11Nov 19
24°FOct 26Nov 1Nov 5Nov 9Nov 13Nov 17Nov 23Nov 29Dec 8
20°FNov 4Nov 11Nov 17Nov 23Nov 28Dec 3Dec 9Dec 20Jan 2
16°FNov 12Nov 23Nov 30Dec 7Dec 13Dec 23Jan 2Jan 14Feb 2

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°F181174168164161157153149143
32°F210204198193188184179174167
28°F242231227222218213209203194
24°F282270262256250244238232224
20°F327311303295287276269261248
16°F363344334325315308300289271

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
91% 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
4,852
Cooling degree days, base 65°F
876
Growing degree days, base 40°F
5,692
Growing degree days, base 45°F
4,350
Growing degree days, base 50°F
3,212
Growing degree days, base 55°F
2,267
Growing degree days, base 60°F
1,487

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January91901
February73103
March598024
April3632119
May14941357
June34129545
July3333795
August4294755
September7276455
October3732141
November687016
December91902

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 1 km from Boardman. 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 USC00350858 (Boardman). Public domain.