It's crazy: when it's RAINING, it makes no sense to me that PEOPLEDRIVE 10 miles an hour faster than they NORMALLY would, but then the other thing that makes no sense is when people drive 30 miles an hour slower than normal.
A dog doesn't care if you're TIRED or it's raining. It WANTS to go out - and if it doesn't go out, it's GOING to be mournfully FOLLOWING you around the HOUSE for the whole evening.