We will start this article by saying in no way, shape or form am I recommending that YOU, as an inexperienced (in pressure washing) homeowner every operate a pressure washer in the rain or any inclement weather for that matter. With that said the answer is yes, not only do most powerwashing contractors work in the rain, many of us prefer it.
If you have a pressure washer that was manufactured in the past couple of decades by a legit company common sense tells you that the machine itself should be okay if rained on… I mean come on it is made to spray upwards of 5 gallons of water a minute. If you still have doubt regarding using your machine and inclement weather just look for a UL rating on the machine. If the pressure washer has a UL rating you are good to go, if not wait for a sunny day.
UL is a global independent safety science company with more than a century of expertise innovating safety solutions from the public adoption of electricity to new breakthroughs in sustainability, renewable energy and nanotechnology. Dedicated to promoting safe living and working environments, UL helps safeguard people, products and places in important ways, facilitating trade and providing peace of mind.
With that said we would still recommend keeping your pressure washer in a place where it will not get wet because miracles do happen. Keep in mind that regular pressure washing safety guidelines still apply.