In reply to georgeevans88:
I've never known Avernus to be dry! It's graded for standard (damp) conditions....
If there's an on-shore (anything between SW and SE) breeze and humidity is relatively low, then Astrid will be OK as long as you don't mind steep jug-hauling. Also, if you get on it in the early morning, you could have some direct sun helping to keep it dry.
Mars is a massive step-up and more likely to be damp (as it's further into the zawn) and it's much, much harder.
Good luck - they are both brilliant routes.