Arizona is a gateway for migrating monarchs flying through our region each Spring and Fall from both California and Mexico. From the floors of the lower deserts rising to the high Colorado plateau, monarchs encounter a multitude of climate zones, each with its own gifts of abundant milkweed species and nectar as well as many challenges. As Dr. Fred Urquhart once noted when studying monarchs in our state, Arizona is also a winter home to small numbers of monarchs in the lower deserts each year, some breeding, others nonbreeding.
Arizona is second only to Texas in the sheer number of approximately 30 native Asclepias (milkweed) species across our multiple elevations and climate zones. We are unique in hosting evergreen milkweeds in the lower deserts, always available to monarchs whenever they visit our way.
Monarchs are present in Arizona all year, but no single location has monarchs present throughout all twelve months. Every year monarchs leave the hotter desert locations in May as high temperatures soar above 100°F. They can still be found in the higher elevations of the state especially above 7,000 feet elevation during the summer months. We welcome their return to the middle and lower elevations each Fall.
Community Science Opportunities
Journey North: Since 2007 monarch enthusiasts in Arizona have reported monarch sightings to Journey North. Send your monarch sightings here to add to this important knowledge bank: Journey North Monarch Sightings. To help everyone understand the importance and movement of monarchs West of the Rocky Mountains we now partner with Journey North to provide Western Monarch News during the Spring and Fall Migrations.
Read more here: Journey North Western Monarch Migration Update.
We are especially looking for sighting information of monarchs on native milkweed or on any nectar sources to learn more about their preferences.
Tagging season begins in late August and we invite you to order tags from the Southwest Monarch
Study if you live in Arizona, New Mexico, Utah, Nevada or western Colorado. (Currently tagging in California is not permitted without a CDFW permit.) Every year we learn something new about the monarch migration in the Southwest that varies from Mexico to coastal California and sometimes in between.
New to tagging? Learn how! How to tag a monarch
Interested? Order tags. Request tags from the Southwest Monarch Study
Southwest Monarch Study Recovery Map. Southwest Monarch Study Tagging Recovery Map
Monarch Larva Monitoring Project offers training for weekly monitoring of your milkweed patch.
Integrated Monarch Monitoring Program is a national program to collect milkweed, nectar plant, and monarch use data from a variety of land-use types and regions.
Project Monarch Health is a citizen science project training volunteers to sample wild monarchs to help track the spread of a protozoan parasite across North America.
Southwest Monarch Study and Gila Watershed Partnership will be adding 3,000 native milkweed stems awarded by a NFWF Grant in partnership with Arizona State Parks, Arizona Game & Fish, U. S. Fish and Wildlife Refuges, two mines and more this summer.
Southwest Monarch Study