Frost Dates for Union, OR

Frost Dates

Last Spring Frost (50%) iA 50% chance that the last spring frost has already passed by this date. Most gardeners use this as their primary planting guide. May 11
First Fall Frost (50%) iA 50% chance that the first fall frost has occurred by this date. Plan to harvest or protect tender plants before this date. September 26
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

30% Probability iOnly a 30% chance of frost remaining by this date. Use these dates for a safer planting window, especially for tender plants sensitive to cold.

Last Spring Frost May 19
First Fall Frost September 20

Hard Freeze (28°F / -2°C)

Last Spring Hard Freeze April 24
First Fall Hard Freeze October 7
45.20°N, -117.86°W © OpenStreetMap

Growing Season

138 Days May 11 to September 26

USDA Hardiness Zone iHardiness zones indicate which perennial plants can survive winter in your area. For annual vegetables, frost dates and growing season length matter more than hardiness zone.

Zone 6b

Learn more

Temperature

20° 40° 60° 80°
33°
High: 40°
Avg: 33°
Low: 25°
Jan
36°
High: 45°
Avg: 36°
Low: 27°
Feb
42°
High: 53°
Avg: 42°
Low: 31°
Mar
47°
High: 59°
Avg: 47°
Low: 34°
Apr
55°
High: 68°
Avg: 55°
Low: 41°
May
61°
High: 74°
Avg: 61°
Low: 47°
Jun
68°
High: 86°
Avg: 68°
Low: 51°
Jul
69°
High: 87°
Avg: 69°
Low: 50°
Aug
60°
High: 77°
Avg: 60°
Low: 43°
Sep
49°
High: 63°
Avg: 49°
Low: 34°
Oct
39°
High: 48°
Avg: 39°
Low: 31°
Nov
32°
High: 39°
Avg: 32°
Low: 25°
Dec
32°F
28°F
Avg High Avg Temp Avg Low Light Frost (32°F) Hard Frost (28°F)

Precipitation

0" 1" 2" 3" 3.1"
1.4"
1.41"
Jan
1.3"
1.26"
Feb
1.8"
1.81"
Mar
2.5"
2.51"
Apr
3.1"
3.08"
May
2.5"
2.52"
Jun
2.2"
2.23"
Jul
2.2"
2.17"
Aug
2.3"
2.28"
Sep
2.2"
2.17"
Oct
2.0"
2.04"
Nov
1.9"
1.86"
Dec

Sunrise / Sunset

4a7a10a1p4p7p10pNoonJanFebMarAprMayJunJulAugSepOctNovDec9h10h12h13h15h15h15h14h12h11h9h9h
Jan: 7:32 AM – 4:28 PM · 8h 55m
Feb: 6:55 AM – 5:05 PM · 10h 10m
Mar: 6:11 AM – 5:49 PM · 11h 37m
Apr: 5:22 AM – 6:38 PM · 13h 17m
May: 4:40 AM – 7:20 PM · 14h 40m
Jun: 4:17 AM – 7:43 PM · 15h 26m
Jul: 4:26 AM – 7:34 PM · 15h 07m
Aug: 5:03 AM – 6:57 PM · 13h 54m
Sep: 5:51 AM – 6:09 PM · 12h 18m
Oct: 6:39 AM – 5:21 PM · 10h 42m
Nov: 7:22 AM – 4:38 PM · 9h 16m
Dec: 7:43 AM – 4:17 PM · 8h 34m
Daylight Longest: 15h 27m · Shortest: 8h 33m

Nearby Stations

La Grande, ORMay 6 - October 1 Baker City Muni AP, OR May 25 - September 15 Elgin, ORMay 24 - September 18 Wallowa, ORJune 7 - September 9 Joseph, ORMay 24 - October 1 Meacham, OR

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