If you’ve ever stood on the banks of the Columbia River in Wahkiakum County, you know the air feels different here. It’s heavy, salt-tinged, and often moving. Honestly, looking up "weather for Cathlamet WA" on a generic app usually gives you a half-truth at best. People see a rainy forecast and cancel their trips. Huge mistake.
Cathlamet doesn't just "have weather." It has a temperament.
The Current Mood in Cathlamet
Right now, as of January 17, 2026, the town is defying its "overcast winter" reputation. It is 41°F outside, but with the wind coming off the water from the southeast at 6 mph, it feels like 37°F. It’s clear. It’s crisp.
The humidity is sitting at 69%. That’s actually low for this time of year—usually, January in Cathlamet feels like living inside a damp wool sweater with 94% humidity. Today is a rare, sunny gift. We’re looking at a high of 54°F today and tomorrow, which is nearly ten degrees warmer than the historical average for January.
Enjoy it while it lasts. By next Sunday, January 25, the sky is expected to open up with heavy rain and a 75% chance of precipitation. That’s the Cathlamet most people know.
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Why the "Wet" Reputation is Misleading
Most visitors think Cathlamet is just a smaller, rainier version of Seattle. Not really. Because it's tucked right against the river and influenced by the Pacific gap, the precipitation patterns are aggressive but specific.
November is actually the wettest month, averaging about 12 inches of rain. Compare that to July, where you might only see 1.4 inches. You’ve got this massive swing between a "cool season" that lasts from mid-November to mid-February and a "warm season" that kicks off in late June.
Kinda wild, right? You can go from needing a heavy-duty Grundéns rain parka in December to sitting on a dock in 74°F heat in August.
Temperature Reality Check
- The Winter Floor: December 30 is typically the coldest day, bottoming out at 37°F.
- The Summer Ceiling: August 2 is the peak, hitting a comfortable 74°F.
- The Humidity Factor: It’s almost always humid here (rarely dropping below 81%), but it’s a "cool humid," not the sticky, oppressive heat you’d find in the South.
Microclimates and the River Effect
The Columbia River acts like a giant thermal regulator. In the summer, the water stays cool, keeping the town from hitting the triple-digit heatwaves that sometimes bake Portland or Vancouver. In the winter, the water is often warmer than the air, which can create that moody, thick fog Cathlamet is famous for.
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If you're driving in from the east, you'll notice the clouds often "stack" against the hills behind the town. This means it might be pouring in the woods but just misty on Main Street.
Packing for the Wahkiakum Shift
If you are heading here, don't trust the sun. A "sunny" January day like today can turn into a bone-chilling evening the second that southeast wind picks up.
Basically, the "Cathlamet Uniform" exists for a reason:
- Waterproof Shell: Not a "water-resistant" hoodie. An actual shell.
- Wool Layers: Synthetics are okay, but wool stays warm when the 88% humidity eventually soaks through your layers.
- Footwear: If you aren't wearing boots with good grip, the mossy docks and wet trails will take you out.
Honestly, the best time to visit if you hate the rain is mid-May through September. August is the clear winner for sky clarity, with clear or partly cloudy skies about 73% of the time.
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Real Expert Tips for Navigating Cathlamet Weather
Stop checking the national news for this area. Look at the local river gauges and the "Mist, OR" station data if you want a better idea of what's blowing in from the coast.
If the wind is from the southwest, expect moisture within the hour. If it’s from the east or southeast, like it is today, you might just get lucky with a dry spell.
Actionable Insights:
- Monitor the Dew Point: In Cathlamet, the dew point is a better indicator of "misery" than the actual temperature. If it's creeping up, it’s going to feel much colder or hotter than the thermometer says.
- Watch the River: If the whitecaps are heading upriver, the wind is strong enough to drop the "feels like" temperature by at least 5-10 degrees.
- Plan for "Sun Breaks": Even on the 75% rain days predicted for late January, "sun breaks" are common. Keep your gear in the car and be ready to move when the clouds split.