24.4 Million Birds Detected on Radar Overnight Across Pennsylvania Including Pittsburgh State College and Harrisburg Wednesday Morning May 13
PENNSYLVANIA — An estimated 24.4 million birds crossed Pennsylvania overnight on May 12 into May 13, producing one of the largest single-night spring migration events ever recorded across the state according to Birdcast. What appeared to be widespread rainfall on radar was actually a massive wall of migrating birds blanketing nearly the entire Pennsylvania radar footprint. The State College radar site provided the clearest signal of the event as actual rain interfered with western Pennsylvania readings near Pittsburgh overnight.
Migration activity is expected to drop significantly over the next two nights as unsettled weather moves across the region, though flights will not stop entirely during this period.
All Pennsylvania Radar Sites Captured the Statewide Migration Signal Overnight
Every radar site across Pennsylvania picked up the extraordinary bird migration signature overnight, confirming the event was truly statewide in scale. The dashed boundary visible on radar imagery clearly separates actual precipitation pushing through western Pennsylvania from the pure bird migration return covering central and eastern portions of the state.
That level of separation and clarity across multiple radar sites simultaneously reflects just how remarkable the volume of migrating birds was during this single overnight flight across Pennsylvania.
Migration Expected to Slow Over Next Two Nights Due to Unsettled Weather
Despite the record-scale overnight event, unsettled weather arriving across Pennsylvania will suppress migration activity for the next two nights. Conditions favorable for large migration flights require calm and clear skies, and the incoming weather pattern will limit how many birds attempt the crossing during this window.
Residents can support migrating birds by keeping feeders clean, providing fresh water, and reducing outdoor artificial lighting at night to avoid disorienting birds still making their way through the region. Stay with NapervilleLocal.com for the latest weather updates and local forecast coverage.
I’ve lived in Naperville long enough to see how quickly our community changes — from new developments downtown to sudden shifts in our Midwest weather. Reporting on Naperville news and daily forecasts gives me the chance to keep neighbors informed about what really matters. My goal is simple: deliver clear, timely updates so you always know what’s happening in our city and what to expect from the skies above.