Starting on January 13th, 2026, specific MDN sites will be following a two week collection period protocol. When the MDN sample data is processed for this period, a new field will be added to the site download CSV to identify which sites are using a 1 week protocol, and which are using the 2 week protocol.
Sites may only change protocol at the start of the calendar year, so samples throughout the year should always be collected using the same protocol. Metadata details concerning the protocol may be found in the metadata section of the MDN network page.
For 2026, the following sites are using the 2 week collection protocol: BC16, CA75, CO99, IN34, KY10, MA01, ME98, MT05, NF19, NS01, OH16, ON07, SK27, TN11, VA28, WY08.