If you are hard core enough you can ride all but maybe a couple months out of the year. The International Motorcycle Show is always the first of December and I have ridden to it a couple of times. This year it was really just partly cloudy and around 40 in the morning and I seriously considered riding to it but mid afternoon it started to snow.
We usually try to do a Resolution Ride on New Years Day. We have had instances where we were riding in the snow and times like this year where it was about 40 and dry and we had a great time.
The past few weeks have been pretty good with days in the mid 50s and down to mid 30s at night. The thing that you have to remember is that you can go from sea level to a few thousand feet in a couple hours ride.
The cool thing about living in Blaine though would be that you would have the choice of all the roads in Washington plus being able to pop over the border to BC and check out all the roads up there. Check out
www.destinationhighways.com They publish the definitive motorcycle guide book for both BC and Washington.