Monarch Butterfly Migration California 2024. Arriving in october, monarch butterflies cluster together on pine, cypress and eucalyptus trees. Stephanie turcotte reports that from february 16th to february 23rd, 2024, observations in pacific grove, ca, revealed notable shifts in monarch butterfly behavior and population.
In the 1980s and ’90s, more than a million made the trip. Volunteers helping to track monarch butterfly migration and milkweed phenology across north america.