how late in the season to go

[dongdong1612]

Looking at doing the TA coat-to-coast starting in N. Carolina and Ending up in Seattle, Wa.  Plan to merge onto the Trans-America route for most of the ride, and average 85 miles/day
How late in  the season can I leave, or better yet, by when should I plan to be in Missoula to ride the rest to the Pacific coast?  I prefer not to be riding in winter type weather (snow/sleet), although I know you can never rule out snow in the Rockies in September.. 
Thanks for any advise on the topic!

[jamawani]

A mid-July departure will put you in Missoula in early Sept. and Seattle about Sept. 21.
(Depending on where you start in NC, where you merge with the T.A., and route to Seattle)
4500 miles; 500 miles/week; weather, mechanical, sickness delays accounted for.

But - - -
Leaving from NC on July 16th with put you in the worst of summer heat & humidity in the east.
I could not think of a nastier, hotter, sweatier time frame to ride east-to-west.

[fastrog]

Don't start too late. My wife was out of the country, so I started Transam in Yorktown in late June. Hit a 102-103 heat wave and suffered a lot. Expect to get snow or sleet any time of the year in parts of the West. I have gone through sleet in Montana's Big Hole (on the route) and over several passes, and in Yellowstone. In July and August.