There could be many reasons why you want your dog to stay in the doghouse -- instead of letting him inside your home -- when it's raining. No matter the reason, though, keep in mind that your dog is unlikely to stay there if you use the doghouse as a punishment place or if you try to force him in. Instead, make the doghouse comfortable and inviting and he'll start to think of it as a refuge during both good and bad weather.
Check that water is not getting into the doghouse. Poorly constructed doghouses might have gaps between panels, holes or cracks that are allowing water to leak in. The result: Rover will refuse to stay inside as soon as it starts to rain. If you find any openings, seal them using sealant -- the kind you use to seal water leaks inside the house -- or wall putty, depending on what the doghouse is made of.
Move the doghouse to a better protected area. During storms, dogs might want to hide and run away from the thunder or wind. If the doghouse is in the middle of the yard, it could feel too exposed. Try moving it close to your house or placing it under a porch or near a wall.
Make the place as comfy as possible. Add a bed, water dish and chewy or toy to the house. If the doghouse feels more like a safe heaven than a cage, he'll learn to think of it as a good place to seek refuge when it rains. Ideally, the doghouse should be big enough for your dog to stand in, turn around and lie down comfortably. Plus, the bedding shouldn't cover the entire floor, so the water bowl can stand on the floor of the doghouse instead of the bed.