Baker City climate

Baker City Frost Dates and Growing Season

NOAA 1991-2020 normals for Baker City Muni AP, 7.8 km from Baker City, elevation 3361 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Baker City 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 25 and the first fall freeze around September 15, a growing season of about 111 days.

Median at 32°F
last May 25, first September 15
Median at 28°F
last May 8, first September 27

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°F–––––––––
32°FJun 16Jun 9Jun 4May 30May 25May 22May 17May 13May 9
28°FMay 23May 17May 13May 10May 8May 5May 3Apr 30Apr 25
24°FMay 10May 4May 1Apr 28Apr 26Apr 23Apr 19Apr 15Apr 8
20°FApr 28Apr 21Apr 16Apr 11Apr 6Apr 2Mar 28Mar 19Mar 9
16°FApr 6Mar 28Mar 16Mar 9Mar 4Feb 28Feb 25Feb 19Feb 12

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°F–––––––––
32°FSep 2Sep 6Sep 9Sep 12Sep 15Sep 18Sep 21Sep 24Oct 1
28°FSep 12Sep 17Sep 21Sep 24Sep 27Sep 30Oct 2Oct 5Oct 9
24°FSep 24Sep 29Oct 2Oct 5Oct 7Oct 11Oct 14Oct 19Oct 25
20°FOct 5Oct 10Oct 14Oct 18Oct 21Oct 25Oct 29Nov 2Nov 9
16°FOct 17Oct 23Oct 28Nov 1Nov 4Nov 9Nov 14Nov 21Nov 26

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°F999185817670655848
32°F1331251201151111061009485
28°F160154148144140136132127120
24°F189179174169165160156152145
20°F232219210203197192186181170
16°F275264255249243237230222210

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
6,655
Cooling degree days, base 65°F
324
Growing degree days, base 40°F
3,980
Growing degree days, base 45°F
2,888
Growing degree days, base 50°F
1,993
Growing degree days, base 55°F
1,274
Growing degree days, base 60°F
716

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January1,12200
February88100
March75006
April575033
May3405170
June16229320
July32142575
August40124549
September20325282
October557054
November86404
December1,13000

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 7.8 km from Baker City. 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 USW00024130 (Baker City Muni AP). Public domain.