I generally don't clean in the rain, but today I stuck it out and worked round the showers and ended up with a good day.
Customers don't normally complain, in my experience, especially when the weather is so bad for so long.
But it is a pain, sat in your vehicle, reading all the naff bits of a newspaper that you wouldn't normally read, waiting for the rain to stop lashing down.
However, if window cleaning was a job which entailed a nice working environment, there'd be far far more window cleaners about and you wouldn't be to price as good as what you're capable of.