Blaine climate

Blaine Frost Dates and Growing Season

NOAA 1991-2020 normals for Blaine, 3.8 km from Blaine, elevation 60 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Blaine. 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 March 31 and the first fall freeze around November 4, a growing season of about 219 days.

Median at 36°F
last April 23, first October 20
Median at 32°F
last March 31, first November 4
Median at 28°F
last March 5, first November 19

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 12May 4May 1Apr 28Apr 23Apr 17Apr 12Apr 7Apr 1
32°FApr 22Apr 12Apr 7Apr 3Mar 31Mar 26Mar 21Mar 15Mar 8
28°FMar 31Mar 21Mar 15Mar 10Mar 5Feb 28Feb 25Feb 17Feb 2
24°FMar 8Feb 28Feb 25Feb 18Feb 10Jan 31Jan 23Jan 12Jan 2
20°FFeb 25Feb 16Feb 3Jan 27Jan 18Jan 11Jan 3Dec 25Dec 8
16°FFeb 12Jan 30Jan 25Jan 16Jan 9Jan 2Dec 28Dec 17Dec 7

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°FOct 4Oct 8Oct 12Oct 16Oct 20Oct 23Oct 27Oct 31Nov 6
32°FOct 18Oct 24Oct 29Nov 1Nov 4Nov 8Nov 12Nov 17Nov 24
28°FOct 30Nov 6Nov 11Nov 15Nov 19Nov 24Nov 28Dec 5Dec 16
24°FNov 12Nov 20Nov 26Dec 1Dec 6Dec 12Dec 21Dec 31Jan 15
20°FNov 25Dec 1Dec 6Dec 13Dec 23Dec 30Jan 7Jan 17Feb 1
16°FDec 4Dec 10Dec 20Dec 26Jan 1Jan 5Jan 12Jan 24Jan 31

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°F209200193188182177172164155
32°F247237231225219214209201190
28°F295283274265257251244236227
24°F345332319310302294285275262
20°F365365361351341334327317304
16°F365365365365365365360345333

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
97% of years
20°F or colder
73% of years
16°F or colder
36% 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
5,186
Cooling degree days, base 65°F
67
Growing degree days, base 40°F
4,284
Growing degree days, base 45°F
2,866
Growing degree days, base 50°F
1,754
Growing degree days, base 55°F
926
Growing degree days, base 60°F
348

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January79701
February66802
March62309
April458046
May2911183
June1497309
July6229432
August6426428
September1943261
October443071
November638010
December80102

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 3.8 km from Blaine. 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 USC00450729 (Blaine). Public domain.