Honestly, if you’re waking up in Hermiston today, you’ve probably noticed that thick, heavy air hanging over the Columbia Basin. It’s that classic winter "inversion" where the cold air just sits in the valley like a stubborn guest who won't leave the party.
The weather forecast for Hermiston Oregon for Sunday, January 18, 2026, is showing a high of 35°F, but it feels a bit crisper than that. We're currently sitting at 33°F with a light 2 mph breeze coming out of the northeast. It’s the kind of day where you definitely want the heavy coat if you’re heading out to the EOTEC or just grabbing coffee downtown.
What’s Up With the Air Stagnation?
The big story isn't just the cold; it's the Air Stagnation Advisory that the National Weather Service has kept in place. Basically, because there isn't much wind to scrub the atmosphere, all the wood smoke and car exhaust get trapped right where we breathe.
It’s supposed to stay this way until Tuesday at 4:00 PM. If you have asthma or just hate that heavy-air feeling, maybe skip the outdoor jog for a couple of days.
- Current Temp: 33°F (Nighttime)
- Today's High: 35°F
- Tonight's Low: 31°F
- Humidity: 77% (It’s damp out there!)
- Wind: Northeast at 3 mph
There’s a tiny 10% chance of some light snow flurries tonight, but don’t go looking for your sled just yet. It’s mostly going to be cloudy and grey.
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Looking at the Rest of the Week
Looking at the weather forecast for Hermiston Oregon over the next few days, we aren't seeing any massive heatwaves, obviously. Monday and Tuesday look pretty similar, with highs staying in the mid-30s.
The real shift happens later in the week. By Friday, we might actually see 42°F. It’s not exactly tropical, but after a week of "refrigerator temperatures," it’ll feel like a bit of a break.
Why Hermiston Weather is Weird for Farmers
People who aren't from Umatilla County don't always get how the weather here works. We get these hot, baking summers that make our watermelons the sweetest in the world—shoutout to the Hermiston Agricultural Research and Extension Center for proving that science—but our winters are famously "stagnant."
Jacob Powell over at OSU has been talking about how these weirdly mild, damp winters are bringing in things like winter cutworms. These little guys don't mind the 20-degree weather at all. If you're farming wheat or alfalfa around here, this "mild but gray" weather is something you have to watch closely for pest activity.
Quick Tips for the Next 48 Hours:
- Limit Wood Burning: Since we're under that stagnation advisory, local agencies are asking people to go easy on the wood stoves if they can. It helps everyone breathe a little easier.
- Check the Fog: Patchy freezing fog is likely tonight and Monday morning. Highway 395 and I-84 can get dicey fast when that "whiteout" mist rolls in.
- Hydrate Your Plants: Believe it or not, even in winter, that dry basin air can suck the life out of evergreens. If the ground isn't frozen solid, a little water doesn't hurt.
The weather forecast for Hermiston Oregon indicates we are stuck in this cloudy pattern for the foreseeable future. It's typical January stuff for us—nothing too crazy, just cold, gray, and very, very still.
Keep your headlights on during the day if the fog rolls back in. Those gray cars tend to disappear against a gray sky on the way out to Stanfield or Echo. Stay warm, Hermiston.
Next Steps for Staying Safe:
- Monitor Local Air Quality: Keep an eye on the DEQ sensors if you have respiratory issues, as the inversion is expected to last through Tuesday afternoon.
- Winterize Your Commute: Check your tire pressure; these 30-degree swings can cause your TPMS light to pop up even if you don't have a leak.
- Plan for Fog: Allow an extra 10 minutes for your Monday morning commute to account for visibility drops near the river.