Hiyajiru Udon refers to a Zaru Udon-styled home-cooked meal mainly eaten in the summer season in and around Chichibu City including the western part of Saitama Prefecture, Omiya City, Kawagoe City, and Kazo City of Saitama Prefecture.
埼玉県秩父市とその周辺（県西部）、大宮市、川越市、加須市辺りで、主に夏に食されるざるうどん状の家庭料理。