Bend climate

Bend Frost Dates and Growing Season

NOAA 1991-2020 normals for Bend, 2.4 km from Bend, elevation 3660 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Bend. 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 June 6 and the first fall freeze around September 20, a growing season of about 105 days.

Median at 32°F
last June 6, first September 20
Median at 28°F
last May 11, first October 4

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 22Jun 18Jun 14Jun 10Jun 6Jun 3May 30May 24May 17
28°FJun 4May 28May 20May 15May 11May 8May 3Apr 30Apr 25
24°FMay 11May 5May 1Apr 29Apr 25Apr 21Apr 16Apr 11Apr 3
20°FApr 25Apr 17Apr 10Apr 4Mar 31Mar 27Mar 19Mar 11Mar 1
16°FMar 31Mar 22Mar 15Mar 7Mar 1Feb 25Feb 20Feb 14Feb 4

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 3Sep 8Sep 12Sep 16Sep 20Sep 23Sep 26Sep 30Oct 5
28°FSep 18Sep 24Sep 28Oct 1Oct 4Oct 7Oct 11Oct 16Oct 21
24°FOct 3Oct 7Oct 13Oct 17Oct 21Oct 24Oct 28Nov 2Nov 10
20°FOct 18Oct 23Oct 28Nov 1Nov 5Nov 10Nov 15Nov 22Nov 29
16°FOct 27Nov 4Nov 10Nov 15Nov 21Nov 26Dec 1Dec 5Dec 15

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°F948782767267635646
32°F129120114109105100969081
28°F168160154148144139131124114
24°F209198190185180174168162152
20°F256245236227221214208200189
16°F298285277270263255247237224

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
6,561
Cooling degree days, base 65°F
241
Growing degree days, base 40°F
3,732
Growing degree days, base 45°F
2,630
Growing degree days, base 50°F
1,757
Growing degree days, base 55°F
1,079
Growing degree days, base 60°F
573

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January97500
February84001
March78606
April627028
May4185126
June23521251
July67104502
August7188483
September21723273
October517178
November79109
December1,01800

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 2.4 km from Bend. 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 USC00350694 (Bend). Public domain.