Sorry about the link.
Yes, this year is the warmest and driest winter on record in huge areas of the West.
100+ years for most.
The issue will not be snow, but fire.
We had our first fire in the Bighorn foothills in late February.
Normal fire season doesn't start until late July or August.
It is beyond insane.
I'm guessing you might be from the Netherlands.
(You used "de" instead of "the" in one of your posts - - just once I think.)
Also, I'm guessing from your many posts that you intend to do the GDMBR with a few variations.
I have been caught in the Backcountry by fires during the Yellowstone Fires year - 1988.
I ended up helping the caterer serve meals to the fire crews. Change of plans for sure.
Unless we get some intense spring snows in the mountains and rain in late spring
it may be the worst fire year in history - the Canadian West has had bad fires the past few years.
Inciweb is the U.S. govt. website for fire reporting.
https://inciweb.wildfire.gov/The fires showing up now are prescribed burns - but I hope they stop soon.
There was a huge prescribed burn that got out of hand at Yosemite a few years ago.
When there is high fire risk - large sections of national forest are closed to entry.
Two of the challenges of long tours in the West are snow in late spring and fires in late summer.
Not to mention the remoteness & lack of services. Europeans sometimes find it hard to believe.
Also, cell phone service is hardly guaranteed. In fact, coverage is limited.
I know you have to make final plans and purchase tickets, get tourist visa, etc.
My bet would be mid-May to mid-July - if you are planning 8 weeks for the GDMBR.
That would put you in Southern Colorado in the first week of June.