WhenToBird

3 oriole species in Montana

When Do Orioles Arrive in Montana?

Adult male Bullock's Oriole
Photo: sprcrkwild, CC BY 4.0 via iNaturalist

Bullock's Orioles, Baltimore Orioles, and Orchard Orioles are the orioles you are most likely to see in Montana. Bullock's Orioles reach Montana in early May, are common by the second week of May, peak in late May (12% of checklists), and most are gone by late July.

Orioles here are the birds (Baltimore, Orchard, Bullock's and relatives), not the baseball team.

When to look

First arrivalsMay 1-7early May
Common byMay 8-14the second week of May
PeakMay 22-31late May
Most gone byJul 22-31late July

Best: late May. First arrivals early May; most are gone by late July. Peak: on about 12% of Montana checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marnot usually seen
  4. Aprnot usually seen
  5. Maypeak season
  6. Junpeak season
  7. Julcommon
  8. Auguncommon
  9. Sepnot usually seen
  10. Octnot usually seen
  11. Novnot usually seen
  12. Decnot usually seen

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

Orioles in Montana, species by species

SpeciesFirst arrivalsCommon byPeakMost gone byPeak %
Bullock's OrioleMay 1-7May 8-14May 22-31Jul 22-3112%
Baltimore OrioleMay 15-21May 15-21Jun 1-7Jun 8-142.4%
Orchard OrioleMay 15-21May 15-21Jun 1-7Jul 15-211.8%
0%5%10%15%Bullock's OrioleBaltimore OrioleOrchard OrioleJanFebMarAprMayJunJulAugSepOctNovDec
  • Bullock's Oriole
  • Baltimore Oriole
  • Orchard Oriole
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 Montana 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 Montana

Best counties for Bullock's Oriole

Share of checklists at the peak
  1. Chouteau CountyBest early June · 56 checklists that week, 954 in all35%
  2. Big Horn CountyBest early June · 50 checklists that week, 1,279 in all34%
  3. Broadwater CountyBest early June · 66 checklists that week, 2,470 in all30%
  4. Musselshell CountyBest late July · 24 checklists that week, 961 in all30%
  5. Custer CountyBest late May · 107 checklists that week, 1,404 in all27%
  6. Cascade CountyBest early June · 353 checklists that week, 16,190 in all27%

Common questions

When do orioles arrive in Montana?
Bullock's Orioles reach Montana in early May, are common by the second week of May, peak in late May (12% of checklists), and most are gone by late July.
When do orioles leave Montana?
Most Bullock's Orioles have left Montana by late July, when reports fall below half their usual rate. Stragglers are still reported until late August.
When is the best time to see orioles in Montana?
The Bullock's Oriole is reported most often in late May, on about 12% of Montana checklists.
Which orioles are in Montana?
Bullock's Oriole, Baltimore Oriole, and Orchard Oriole are reported regularly; the Bullock's Oriole is the most common.