Based on 2,609 research-grade iNaturalist observations in Arizona, Red-winged Blackbird is most often recorded in April; in Arizona it behaves like a seasonal. It ranks #57 among birds recorded in the state in our data.
Agelaius phoeniceus
Red-winged Blackbird in Arizona 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 Arizona in April

Mourning Dove
Gambel's Quail
White-winged Dove
House Finch

Great-tailed Grackle

Curve-billed Thrasher

Gila Woodpecker

Vermilion Flycatcher
Places to look in Arizona
Desert Botanical Garden
Coronado National Forest
Boyce Thompson Arboretum
Tonto National Forest
Yuma Territorial Prison
Apache–Sitgreaves National Forests
FAQ
When does Red-winged Blackbird appear in Arizona?
Mainly December–June, with the most records in April.
How common is Red-winged Blackbird in Arizona?
It ranks #57 by number of iNaturalist observations among birds in Arizona (2,609 records in our sample).