In reply to Mike5:
Don't bother with the rockfax unless you plan to climb at other crags in the area as it's a bit out of date. The local guide is good and can be had for about 15 Euros at the campsite.
If you like super steep and juggy go to Cascade. For slightly less steep and more techy go to Berlin. For vertical go to un pont. The newer routes down the far right of the crag are really great too. No point in recommending particular routes because they're all great!
As for whether, not sure, but if it's sunny you'll be able to climb all day in the sun if you need to by changing sectors (the opposite of what you do in the summer)