I was thinking of trying to ride the HONC route this weekend.

Is anybody local able to say whether with the recent moist weather is it going to be a slippery mud-fest?

Cheers

It’ll be damp/slippy in places, but not too bad (although I can only speak with confidence about the 50k route).

Be aware though, some of the route is on tracks that are not a right of way (including, I think, most of the first climb), permission was specifically given for use for the event. You will have to work out a detour around those bits.