When do ospreys leave Idaho?

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

When is the best time to see ospreys in Idaho?

The Osprey is reported most often in mid August, on about 16% of Idaho checklists.

Osprey · Pandion haliaetus

When Do Ospreys Arrive in Idaho?

Photo: Bill Levine, CC BY 4.0 via iNaturalist

Ospreys reach Idaho in mid March, are common by early April, peak in mid August (16% of checklists), and most are gone by late September.

When to look

First arrivalsMar 15-21mid March

Common byApr 1-7early April

PeakAug 15-21mid August

Most gone bySep 22-30late September

Best: mid August. First arrivals mid March; most are gone by late September. Peak: on about 16% of Idaho checklists.

Jannot usually seen
Febnot usually seen
Maruncommon
Aprpeak season
Maypeak season
Junpeak season
Julpeak season
Augpeak season
Seppeak season
Octuncommon
Novrare
Decnot usually seen

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

Ospreys in Idaho, species by species

Species	First arrivals	Common by	Peak	Most gone by	Peak %
Osprey	Mar 15-21	Apr 1-7	Aug 15-21	Sep 22-30	16%

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 Idaho 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 Idaho

Best counties for Osprey

Share of checklists at the peak

Kootenai CountyBest early August · 149 checklists that week, 8,249 in all43%
Nez Perce CountyBest mid August · 142 checklists that week, 10,708 in all40%
Fremont CountyBest late August · 158 checklists that week, 5,201 in all39%
Bonneville CountyBest mid August · 149 checklists that week, 6,998 in all38%
Lewis CountyBest mid August · 12 checklists that week, 603 in all38%
Valley CountyBest mid August · 238 checklists that week, 8,991 in all37%

Common questions

When do ospreys arrive in Idaho?: Ospreys reach Idaho in mid March, are common by early April, peak in mid August (16% of checklists), and most are gone by late September.
When do ospreys leave Idaho?: Most Ospreys have left Idaho by late September, when reports fall below half their usual rate. Stragglers are still reported until late October.
When is the best time to see ospreys in Idaho?: The Osprey is reported most often in mid August, on about 16% of Idaho checklists.