The laws are the same for tourists, as for residents. Anyone 21 years or older, in Washington State, may purchase and hold up to 1 ounce of useable marijuana, up to 16 ounces of marijuana infused product, like brownies, and up to 72 ounces of liquid marijuana product. Paraphernalia is also legal. You can partake on private property, away from the view of the general public. Do remember, that some hotels are non-smoking and if they don’t allow tobacco smoke, they won’t allow marijuana smoke, either.
Actually the laws are stricter than some states when it comes to marijuana in Washington. The same provisions apply to tourists. While laws have been enacted “decriminalizing” recreational use, under federal law you can and will be charged. The only way to be safe is to smoke only in private areas away from the general public. You may purchase your weed here at a dispensary as a safer option then carrying it on your person or vehicle.
The marijuana laws of Washington are not any different for tourists than they are for locals. You must be an adult of twenty one years of age or older. You may purchase and possess no more than one ounce of marijuana. You also cannot consume the marijuana in view of the general public.