I messaged a new ish customer last night only cleaned it twice .
She said its forecast rain tomorrow

Well duh its been raining for a month what do you think ive been doing......
The reason I dont tell them i clean in rain when I take them on is because that puts the question in their head. If I said oh please let us clean in rain it will be fine, it breeds doubt. I just say of course I clean in rain it makes no difference. That's the confidence you need, you also need the attitude of im too busy to play games if you dont appreciate the reliable service i will find some who does. And oddly there are people out there that appreciate your effort.
The only choice she has is to have them cleaned or find someone else.
Stop letting people dictate your business.