IMO there is no need to work in the rain, and, in fact, there's more to be gained by not working in the rain than there is by carrying on regardless.
Many people just look at the loss of earnings from not working in the rain.
When starting my business up I decided that I was not going to work in any sort of wet and blustery weather. (also strong winds on dry days in summer blowing dust around when wfp ) As a customer of a window cleaner before starting my own business, I would of not been happy to pay for windows cleaned in the rain, so why clean my customers?
How has this worked out for me?
Well 99% of our work is domestic and verbally agreed with the house holder to be cleaned every 4 weeks, this means 13 cleans a year. We never hit 13 cleans, our average across the business is 12 cleans per year. (customers NEVER complains if we are late, in fact 99% don't even notice or are even bothered)
So whats the up side to not cleaning in the rain?? It needs to be pretty good as we have lost 1 clean in the year on all our domestic customers.
So what is it?
BUSINESS GROWTH
IMO, if you are wanting to build the ultimate one/two man round, top prices, no messers, etc etc, then cleaning in the rain is fine. It's fine because you are not looking for every possible customer you can get in your area, you are only needing enough for you and maybe a helper or partner.
BUT, if you are wanting to build a large business and build it QUICKLY, one that you can manage off the tools and put your name too it, then customer service HAS too come before your own personal earnings, and, IMO, cleaning in the rain falls short on providing a quality, value for money service. Call me Steve Jobs (read the book and you will know), but that's just the way I am.
For the past few years we have asked every new customer for feed back after the first clean and what they expect from us. YOU WOULD BE AMAZED at what customers expect, AND, this is the most important bit of my novel I'm writing here, the reasons why they have changed window cleaner or not had one for a while. AMAZED. Number 2 on our list of reasons for cancelling a window cleaning service is having them cleaned in the rain.
Hope these comments help if you are reading this and trying to decide whether to clean or not to clean in the rain.