Mattawa Weather in August
Average highs run from 94°F on August 1 to 86°F on August 31, and lows from 68°F to 62°F. Normal precipitation for the month is 0.08 in over about 1 wet days.
August day by day
The normal high and low for each date, and the record, in °F.
- Normal low
- Normal high
- Record high
- Record low
August at a glance
- Average high
- 90°F
- Average low
- 66°F
- Precipitation
- 0.08 in
- Record high
- 105°FAug 18, 2023
- Record low
- 29°FAug 15, 2020
- Chance of a freeze
- 0%
- Days of 90°F or more
- 17.6
- Daylight
- 14 h 51 min to 13 h 22 min
- Cloud cover
- 31%
- Humidity
- 43%
- Dew point
- 46°F
- Wind
- 7.2 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 |
|---|---|---|---|---|---|---|
| Aug 1 | 94°F | 68°F | 104°F 2015 | 42°F 2002 | 4% | 0% |
| Aug 2 | 94°F | 68°F | 104°F 2009 | 42°F 2008 | 4% | 0% |
| Aug 3 | 93°F | 68°F | 100°F 2015 | 41°F 2002 | 4% | 0% |
| Aug 4 | 93°F | 68°F | 100°F 1999 | 45°F 2002 | 4% | 0% |
| Aug 5 | 93°F | 68°F | 100°F 2014 | 40°F 2002 | 4% | 0% |
| Aug 6 | 93°F | 68°F | 102°F 2005 | 40°F 2002 | 4% | 0% |
| Aug 7 | 93°F | 68°F | 102°F 2005 | 41°F 2002 | 4% | 0% |
| Aug 8 | 93°F | 68°F | 101°F 2019 | 44°F 2002 | 4% | 0% |
| Aug 9 | 92°F | 68°F | 100°F 2022 | 32°F 2020 | 4% | 0% |
| Aug 10 | 92°F | 67°F | 103°F 2018 | 46°F 2007 | 4% | 0% |
| Aug 11 | 92°F | 67°F | 100°F 2001 | 45°F 2007 | 4% | 0% |
| Aug 12 | 92°F | 67°F | 101°F 2025 | 43°F 2000 | 4% | 0% |
| Aug 13 | 91°F | 67°F | 100°F 2004 | 37°F 2020 | 4% | 0% |
| Aug 14 | 91°F | 67°F | 104°F 2001 | 33°F 2020 | 4% | 0% |
| Aug 15 | 91°F | 66°F | 102°F 2001 | 29°F 2020 | 4% | 0% |
| Aug 16 | 90°F | 66°F | 104°F 2023 | 43°F 2000 | 4% | 0% |
| Aug 17 | 90°F | 66°F | 102°F 2008 | 45°F 2000 | 4% | 0% |
| Aug 18 | 90°F | 66°F | 105°F 2023 | 44°F 2002 | 4% | 0% |
| Aug 19 | 90°F | 66°F | 100°F 2020 | 43°F 2000 | 4% | 0% |
| Aug 20 | 89°F | 65°F | 97°F 2004 | 42°F 2000 | 4% | 0% |
| Aug 21 | 89°F | 65°F | 101°F 2009 | 44°F 2000 | 4% | 0% |
| Aug 22 | 89°F | 65°F | 98°F 2005 | 42°F 2008 | 4% | 0% |
| Aug 23 | 88°F | 65°F | 97°F 2022 | 40°F 2021 | 5% | 0% |
| Aug 24 | 88°F | 64°F | 98°F 2025 | 41°F 2001 | 5% | 0% |
| Aug 25 | 88°F | 64°F | 99°F 2025 | 43°F 2005 | 5% | 0% |
| Aug 26 | 87°F | 64°F | 99°F 2025 | 41°F 2008 | 5% | 0% |
| Aug 27 | 87°F | 64°F | 96°F 2025 | 42°F 2007 | 5% | 0% |
| Aug 28 | 87°F | 63°F | 98°F 2023 | 41°F 2000 | 5% | 0% |
| Aug 29 | 87°F | 63°F | 101°F 2023 | 41°F 2010 | 5% | 0% |
| Aug 30 | 86°F | 63°F | 97°F 2017 | 42°F 2006 | 5% | 0% |
| Aug 31 | 86°F | 62°F | 96°F 2007 | 36°F 1999 | 5% | 0% |
Chance of rain
- Chance of a wet day
- Chance of snowfall
Sunrise and sunset
Times for 2026, local time (PDT).
- August 1
- sunrise 5:40 AM, sunset 8:31 PM
- August 31
- sunrise 6:18 AM, sunset 7:40 PM
Other months
Sources
Normals: NOAA NCEI U.S. Climate Normals, 1991-2020, station USC00456747 (Priest Rapids Dam), public domain. Records: NOAA GHCN-Daily, station USC00457522, 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.