Monarch butterfly spotted late in fall migration

November 3, 2026

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A butterfly was recorded on 2026-10-27 in San Francisco, during the late phase of fall migration toward California coastal overwintering groves.¹ Migration peaks around October 18 but continues through December, with this observation documenting passage still occurring nine days past the typical peak.¹ The species is proposed for federal Threatened listing and represents a native insect moving through the peninsula's urban habitat en route to winter sites.¹

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