Weather for September in “Oregon Outback”

September is a crapshoot but early September *should* be pretty good. Once you leave Klamath Falls, if you head north by northeast, you'll generally encounter drier climate. North by northwest you'll probably encounter more precipitation. In the Cascades in September, I've been dumped on and encountered temperatures dipping to the low 40s high 30s one week only to be greeted with bluebird skies and >85* temperatures the week following.

You can order historical weather data for free from weather.gov

Thanks Ian. The route is Klamath Falls, N and eastish, east of Bend, to the Dalles area, and is definitely in the drier part of the state. (From my PCT hike, I unfortunately definitely know you can get tons of rain in Oregon in August and September!).

I assume it's more predictably nice in May? Or maybe not? Trying to balance the rain odds with the heat.

I'll check the historic info… thanks!

I think September would be a great time to go. Generally, the weather is fantastic, although there is always a chance you'll get rain. Cycle Oregon (an annual 7-day ride through different parts of the state) is in September and I think this year's route is in the northern part of the Deschutes river valley, where you'll be heading. Of course, they get hot showers, food and music every night!

Edit: I just read your intended route and agree with Ian about the weather. It's always a gamble, but I think you'll get decent weather; just be prepared for 40s at night and have a comfortable shelter.

Good luck!

Thanks for the info. The route I'm thinking about is 70% dirt and 360 miles or so, Klamath Falls to the Columbia. And then probably down the Columbia to the train in Portland.

Early September is about the best time – crowds gone, bugs gone, weather still good

Occasionally there will be some rain but you're East of the Cascades where there's less rain

I bet it will be hot. 85 F, maybe hotter.

I can't remember off of the top of my head but I believe much of that route will be above 3000' so +1 to what Jerry and Steven said. Probably warm to hot days with some pretty cold nights.

Might end up being pushed into first week of October. I'll make it a go/no go call based on the week out forecast and bring proper tent/raingear/warm clothing in case.

In Portland, at least, it invariably starts pouring the first weekend in October. If my memory of the past 8 years is accurate.

I haven't been east of the Cascades that time of year yet.

"In Portland, at least, it invariably starts pouring the first weekend in October. If my memory of the past 8 years is accurate."

Actually we have had some great weather in October. Yes it does start raining, but there is usually a week or so of good weather in October in the PNW. A number of years ago I spent close to a week in October in the Enchantments in perfect weather. Last year I spent the 21,22, & 23rd in the Bull of the Woods wilderness near PDX. Hiked all three days in a short sleeve shirt!

So we do get some good weather in October, finding it can be the problem!

Last year we were in Portland the first weekend in October…Weather was great, no rain. Hope it repeats again this year, as we're planning to go back the same time.

Definitely hoping any rain gets wrung out partly/mostly by the Cascades. I'll be over in the drier lowlands, so we'll see!

Hey David T, I'm looking at doing the same this year and was wondering how your trip went last year? I'm thinking of starting a bit later, mid october. Idea is to do the whole ride, and when I hit the Columbia turn west and bike to portland to catch a train home. How was the weather last year?? Any advice? Thanks!