When do ospreys leave Iowa?

Most Ospreys have left Iowa by mid October, when reports fall below half their usual rate. Stragglers are still reported until late October.

When is the best time to see ospreys in Iowa?

The Osprey is reported most often in mid September, on about 6.3% of Iowa checklists.

Osprey · Pandion haliaetus

When Do Ospreys Arrive in Iowa?

Photo: Bill Levine, CC BY 4.0 via iNaturalist

Ospreys reach Iowa in late March, are common by early April, peak in mid September (6.3% of checklists), and most are gone by mid October.

When to look

First arrivalsMar 22-31late March

Common byApr 1-7early April

PeakSep 15-21mid September

Most gone byOct 15-21mid October

Best: mid September. First arrivals late March; most are gone by mid October. Peak: on about 6.3% of Iowa checklists.

Jannot usually seen
Febnot usually seen
Maruncommon
Aprcommon
Maycommon
Jununcommon
Julcommon
Augpeak season
Seppeak season
Octpeak season
Novuncommon
Decnot usually seen

Darker months: more checklists report it. Outlined: peak month.

Ospreys in Iowa, species by species

Species	First arrivals	Common by	Peak	Most gone by	Peak %
Osprey	Mar 22-31	Apr 1-7	Sep 15-21	Oct 15-21	6.3%

Osprey

Share of complete checklists reporting each species, by week (4 per month). Gaps: fewer than 10 checklists that week.

Frequency is the share of complete checklists in Iowa that listed the bird, 2016–2025. It is not a head count, and it follows where and when people go birding. How to read it.

Where in Iowa

Best counties for Osprey

Share of checklists at the peak

Montgomery CountyBest mid October · 13 checklists that week, 213 in all33%
Franklin CountyBest the second week of September · 12 checklists that week, 331 in all20%
Marshall CountyBest late September · 93 checklists that week, 3,476 in all20%
Cass CountyBest the second week of October · 16 checklists that week, 449 in all17%
Monroe CountyBest the second week of April · 12 checklists that week, 257 in all17%
Louisa CountyBest mid September · 24 checklists that week, 1,639 in all16%

Common questions

When do ospreys arrive in Iowa?: Ospreys reach Iowa in late March, are common by early April, peak in mid September (6.3% of checklists), and most are gone by mid October.
When do ospreys leave Iowa?: Most Ospreys have left Iowa by mid October, when reports fall below half their usual rate. Stragglers are still reported until late October.
When is the best time to see ospreys in Iowa?: The Osprey is reported most often in mid September, on about 6.3% of Iowa checklists.