Male monarch butterfly, 2008 (photo by Marcy Cunkelman)

14 May 2025

Monarch butterflies (Danaus plexippus) are migrating north and, happily, the first few have arrived in Pennsylvania within the past two weeks.

As of this morning there are 11 monarch butterfly sightings on Journey North’s 2025 spring migration map. Here are six of the 11 including the very first one on 30 April in Philadelphia.

• Philadelphia, Philadelphia County, 4/30/2025
• Pittsburgh, Allegheny County, 5/5/2025
• McKees Rocks, Allegheny County, 5/10/2025
• Pennsylvania Furnace, Centre County, 5/10/2025
• Gettysburg, Adams County, 5/11/2025
• York, York County, 5/12/2025

These sightings were gleaned from the Journey North Monarch (Adult) First Sighting map, shown below in a screenshot frozen in time on 14 May 2025.

Ideally we’ll see a handful more monarchs this year compared to last because …

In March the World Wildlife Fund reported that December 2024’s count of eastern monarch butterflies wintering in Mexico showed the eastern population had nearly doubled since the prior year. This is good news in the very short term but is tempered by a sober look at World Wildlife Fund’s Annual Count graph, embedded below. (Purposely small so that you click here to see the full size graph at WWF.)

The graph shows healthy large populations from 1993-1994 through 2003-2004, then acreage drops off to the worst year of only 1.66 acres (in red) in 2013-2014.

This year’s 4.42 acres (2024-2025) is nearly twice last year’s 2.22 but both are still among the five lowest levels in 32 years. There’s a lot of work to do both here and in Mexico to continue the monarchs’ turnaround. (*)

Meanwhile, watch monarch butterfly migration at the Journey North 2025 monarch map. Click the Play button on the map’s control panel (screenshot below) to see their progress.

Report the ones you see to put them on the map.

(*)For information on the monarchs’ plight see July 2024’s blog: Have You Seen Any Monarchs This Year? and Christine Rickabaugh’s comment about the situation in Mexico.)