Home Postcode finder WA North Cascade North Cascade postcode WA North Cascade is a locality in Western Australia covered by postcode 6445. Postcode 6445 State or territory Western Australia (WA) Region Wa Subs 1 G Flds Add a free North Cascade business listing Be the first listing in North Cascade Common questionsWhat is the postcode for North Cascade?North Cascade, WA has the postcode 6445.What state is North Cascade in?North Cascade is in Western Australia (WA).Does postcode 6445 cover more than one suburb?Yes. Postcode 6445 covers 2 localities, so the postcode alone does not identify North Cascade. Browse other postcodes in Western Australia, or widen the search to every Australian postcode.