At this time of year I see quite a few posts asking when they can hike the Timberline Trail. In addition to my own experience, I went back through the Timberline survey and came with these broad recommendations:
(a) Before July - expect extensive snow, consider this to require specialized skills and equipment. Be prepared for long and difficult snow traverses.
(b) First two weeks of July - still some snow, microspikes are likely to still be needed. Some longer stretches of now, especially on the north and east sections.
(c) After mid July - generally snow free

Of course this will depend on the snowpack and the spring and early summer temperatures that will impact the rate of snow melt. I have written a little more about this here: hikeit.info/2025/04/13/when-to…

@Timberline Trail

When to Hike the Timberline Trail: A Guide to Early-Season Travel - HikeIt

Learn when to hike the Timberline Trail. What to expect if you decide to start early in the hiking season and when the trail is snow free.

^{Matt Bromley (HikeIt)}