Based on 10,661 research-grade iNaturalist observations in California, California Tortoiseshell is most often recorded in May; in California it behaves like a seasonal. It ranks #18 among butterflies recorded in the state in our data.
Nymphalis californica
California Tortoiseshell in California by month
Bars show research-grade observations per month. They mix true seasonality with how often people are outdoors, so treat small numbers with caution.
Also seen in California in May
Variable Checkerspot
Monarch
Gray Buckeye
Umber Skipper
Mourning Cloak
Painted Lady
Western Tiger Swallowtail
California Sister
Places to look in California
Botanical GardenThe Huntington Library, Art Museum, and Botanical Gardens
State ParkHearst Castle
Botanical GardenSan Francisco Botanical Garden
State ParkAnza-Borrego Desert State Park
National ForestAngeles National Forest
National ForestSequoia National Forest
FAQ
When does California Tortoiseshell appear in California?
Mainly May–October, with the most records in May.
How common is California Tortoiseshell in California?
It ranks #18 by number of iNaturalist observations among butterflies in California (10,661 records in our sample).