Not sure if warm is even possible anywhere with water right now. The rogue, green and hells canyon I can promise will not be warm. Sunny yes, warm, doubtful.

The Rio Grande through Big Bend is pretty fantastic, and there are multiple canyons depending on how long you want to go. Some of the lower canyons would take more time than you have even if you teleported to the put-in. It's in the 70s down there right now, cooling off nicely at night. Problem is, it's a bitch to get there. Midland is the closest airport and it's about 4 hours away, and furthermore, it's a hell of a drive from here (good scenery though!), if you don't want to drop a grand on a last minute plane ticket.

If you do want to go to TX, though, PM me and I can get you more info.

The San Juan is a moderate 2 day drive from WA and it looks like it's in the 50s in Bluff, sunny of course. It's also a bit drier trip than one with harder rapids. An old associate of mine fell asleep on a ducky and she floated just fine for several hours through the Goosenecks (not recommended of course, it's too pretty to sleep through there).