Montesano Weather Forecast
- 42
- 63
Increasing Clouds
- 42
- 67
Increasing Clouds
- 51
- 65
Rain Likely
- 50
- 62
Rain
- 48
- 64
Mostly Cloudy
- 47
- 65
Mostly Cloudy
- 45
- 65
Partly Sunny
Today 26 Sep Lower Chehalis River Valley
Mostly sunny. Highs in the mid 60s to lower 70s.
Tonight 26 Sep Lower Chehalis River Valley
Partly cloudy in the evening then becoming mostly cloudy. Lows in the lower to mid 40s. Northeast wind to 10 Mph in the evening becoming light.
Montesano Temperature Statistics
September Temperature
Hoquiam, Bowerman Airport (14.9 miles)
Lowest 20 September, 2026
46.7 °FAverage September
60 °FHighest 17 September, 2026
76.6 °F
Climate (2021–2026)
Hoquiam, Bowerman Airport (14.9 miles)
Average Low 2021–2026
46.3 °FAverage 2021–2026
52.4 °FAverage High 2021–2026
58.6 °F