You want CLIMB or HIKE?
A 3,400 foot hike would be Mt Si, one of the most popular trails in the area. Located about 30 miles east of Seattle along I-90, outside of North Bend. No permit required.
A hike/climb at that time (most likely) would be Granite Mt. I did it two weeks ago and it was a steep snow climb after the first 1.5 miles of trail. It will be more trail in another month (as reported snow is melting faster than usual) but would still be a snow route to the lookout. About 47 miles east of Seattle along I-90 (Exit 47). You need a Trail Pass or risk a fine or park outside the parking lot on the access road.
There are others but as reported, generally, you will run into snow on many of them that early in the season.
Check out
www.wta.org for current reports on hikes, ski trips and some climbs.
A climb up St Helens is about 5,000 feet to about 8,300 ft on a south slope.
Camp Muir on Rainier is also about 5,000 feet to 10,000 ft. Also a south aspect.
The freezing level this weekend is suppose to be down to 3,500 feet and can happen and it does until July in this climate. So you have to be prepared for very firm snow as well as slush.