Redmond climate

Redmond Frost Dates and Growing Season

NOAA 1991-2020 normals for Redmond Roberts Fld, 3.4 km from Redmond, elevation 3043 ft

Frost and the growing season

NOAA's 1991-2020 freeze probabilities for Redmond Roberts Fld. 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 9 and the first fall freeze around September 14, a growing season of about 98 days.

Median at 32°F
last June 9, first September 14
Median at 28°F
last May 14, first September 30

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 26Jun 21Jun 17Jun 13Jun 9Jun 4May 31May 25May 17
28°FJun 9May 31May 25May 19May 14May 10May 6May 3Apr 28
24°FMay 14May 8May 4May 1Apr 28Apr 25Apr 22Apr 17Apr 9
20°FApr 29Apr 23Apr 18Apr 14Apr 9Apr 4Mar 30Mar 24Mar 14
16°FApr 12Apr 3Mar 29Mar 23Mar 17Mar 10Mar 4Feb 25Feb 13

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 1Sep 5Sep 8Sep 12Sep 14Sep 19Sep 22Sep 26Oct 1
28°FSep 14Sep 20Sep 23Sep 27Sep 30Oct 3Oct 5Oct 10Oct 15
24°FSep 29Oct 3Oct 6Oct 9Oct 13Oct 17Oct 19Oct 24Oct 30
20°FOct 8Oct 14Oct 18Oct 22Oct 26Oct 30Nov 2Nov 8Nov 17
16°FOct 20Oct 28Nov 1Nov 5Nov 11Nov 17Nov 21Nov 26Dec 3

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°F878074696358534637
32°F1241151081039893888273
28°F158151145140134129124117107
24°F193184178172167163158152142
20°F233222213207200195188182173
16°F280266255247240232225217205

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
6,172
Cooling degree days, base 65°F
317
Growing degree days, base 40°F
4,080
Growing degree days, base 45°F
2,904
Growing degree days, base 50°F
1,969
Growing degree days, base 55°F
1,244
Growing degree days, base 60°F
694

Growing degree days by month, base 50°F

Heating and cooling by month

MonthHeating DDCooling DDGrowing DD 50
January93801
February79402
March73508
April587033
May3657154
June18333306
July44136558
August53110523
September19230298
October509175
November776012
December99801

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 3.4 km from Redmond. 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 USW00024230 (Redmond Roberts Fld). Public domain.