Monarchs from the east of the Rocky Mountains fly south to overwinter at a single site in southern Mexico. The western populations of Monarchs overwinter at several locations along the coast where conditions are suitable (not too hot, not too cold) for the 5 months (October – February) when suitable milkweed plants are unavailable.
One of the prime Monarch viewing locations is Pismo State Beach near San Luis Obispo. This year, the Monarch population is estimated at 20,000 Plus. The Monarchs perch on Eucalyptus trees in such large numbers the branches bend downward. Most of the time, the butterflies are perched conserving energy, but a swarm is usually present during the day. Western Monarch day, a celebration of the Monarchs will be held on February 4, 2017.