Umatilla Weather in December
Average highs run from 44°F on December 1 to 40°F on December 31, and lows from 32°F to 30°F. Normal precipitation for the month is 1.22 in over about 14 wet days.
December day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
December at a glance
- Average high
- 41°F
- Average low
- 31°F
- Precipitation
- 1.22 in
- Snowfall
- 0.8 in
- Record high
- 75°FDec 15, 2025
- Record low
- -16°FDec 16, 2008
- Chance of a freeze
- 100%
- Daylight
- 8 h 55 min to 8 h 43 min
- Cloud cover
- 74%
- Humidity
- 79%
- Dew point
- 28°F
- Wind
- 8.3 mph
Every day of the month
A wet day has at least 0.01 inch of precipitation; snow means at least 0.1 inch of snowfall.
| Date | Normal high | Normal low | Record high | Record low | Chance wet | Chance of snow |
|---|---|---|---|---|---|---|
| Dec 1 | 44°F | 32°F | 71°F 2021 | 11°F 2014 | 39% | 2% |
| Dec 2 | 44°F | 32°F | 60°F 2008 | 16°F 2009 | 40% | 2% |
| Dec 3 | 43°F | 32°F | 70°F 2007 | 13°F 2013 | 40% | 2% |
| Dec 4 | 43°F | 32°F | 65°F 2007 | 2°F 2013 | 40% | 2% |
| Dec 5 | 43°F | 32°F | 60°F 2023 | 1°F 2013 | 41% | 2% |
| Dec 6 | 43°F | 32°F | 58°F 2015 | 1°F 2013 | 41% | 2% |
| Dec 7 | 42°F | 32°F | 57°F 2025 | -7°F 2013 | 41% | 2% |
| Dec 8 | 42°F | 31°F | 72°F 2015 | -8°F 2013 | 41% | 3% |
| Dec 9 | 42°F | 31°F | 66°F 2015 | -3°F 2013 | 41% | 3% |
| Dec 10 | 42°F | 31°F | 70°F 2025 | -7°F 2009 | 42% | 3% |
| Dec 11 | 41°F | 31°F | 69°F 2014 | -3°F 2009 | 42% | 3% |
| Dec 12 | 41°F | 31°F | 64°F 2025 | 10°F 2013 | 42% | 3% |
| Dec 13 | 41°F | 31°F | 62°F 1998 | 16°F 2009 | 43% | 3% |
| Dec 14 | 41°F | 31°F | 68°F 2002 | 14°F 2008 | 43% | 3% |
| Dec 15 | 41°F | 31°F | 75°F 2025 | -5°F 2008 | 43% | 3% |
| Dec 16 | 41°F | 31°F | 65°F 2025 | -16°F 2008 | 43% | 4% |
| Dec 17 | 41°F | 30°F | 66°F 2025 | -13°F 2016 | 43% | 4% |
| Dec 18 | 41°F | 30°F | 61°F 2025 | 2°F 2008 | 43% | 4% |
| Dec 19 | 40°F | 30°F | 58°F 2020 | 6°F 2008 | 43% | 4% |
| Dec 20 | 40°F | 30°F | 66°F 2019 | -3°F 1998 | 43% | 4% |
| Dec 21 | 40°F | 30°F | 65°F 2019 | -3°F 1998 | 43% | 4% |
| Dec 22 | 40°F | 30°F | 54°F 2014 | -3°F 1998 | 43% | 4% |
| Dec 23 | 40°F | 30°F | 61°F 2013 | -3°F 1998 | 43% | 4% |
| Dec 24 | 40°F | 30°F | 50°F 2003 | 5°F 2017 | 43% | 4% |
| Dec 25 | 40°F | 30°F | 50°F 1998 | 3°F 2008 | 43% | 4% |
| Dec 26 | 40°F | 30°F | 58°F 2024 | 19°F 2004 | 43% | 4% |
| Dec 27 | 40°F | 30°F | 61°F 2022 | 7°F 2021 | 43% | 4% |
| Dec 28 | 40°F | 30°F | 61°F 2011 | 11°F 2021 | 43% | 4% |
| Dec 29 | 40°F | 30°F | 60°F 1998 | 5°F 2021 | 43% | 4% |
| Dec 30 | 40°F | 30°F | 56°F 1998 | 5°F 2003 | 43% | 4% |
| Dec 31 | 40°F | 30°F | 56°F 2020 | -9°F 2021 | 43% | 4% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (PST).
- December 1
- sunrise 7:19 AM, sunset 4:14 PM
- December 31
- sunrise 7:39 AM, sunset 4:22 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00355392 (Mcnary Dam #2), public domain. Records: NOAA GHCN-Daily, station USW00004113, every year on file, quality-flagged values removed. Cloud, humidity, wind and sunshine: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.