Based on 7,692 research-grade iNaturalist observations in California, Checkered White is most often recorded in June; in California it behaves like a summer visitor / breeder. It ranks #23 among butterflies recorded in the state in our data.
Pontia protodice
Checkered White 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 June

Monarch

Gray Buckeye

Western Tiger Swallowtail

Variable Checkerspot

Small White

Anise Swallowtail

California Sister

Pale Swallowtail
Places to look in California
Botanical GardenThe Huntington Library, Art Museum, and Botanical Gardens
State ParkHearst Castle
Botanical GardenSan Francisco Botanical Garden
Anza-Borrego Desert State Park
Angeles National Forest
National ForestSequoia National Forest
FAQ
When does Checkered White appear in California?
Mainly March–October, with the most records in June.
How common is Checkered White in California?
It ranks #23 by number of iNaturalist observations among butterflies in California (7,692 records in our sample).