WhenToBird

2 oriole species in Colorado

When Do Orioles Arrive in Colorado?

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

Bullock's Orioles reach Colorado in late April, are common by early May, peak in mid May (26% of checklists), and most are gone by mid July. They are by far the most reported orioles in Colorado.

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

When to look

First arrivalsApr 22-30late April
Common byMay 1-7early May
PeakMay 15-21mid May
Most gone byJul 15-21mid July

Best: mid May. First arrivals late April; most are gone by mid July. Peak: on about 26% of Colorado checklists.

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

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

Orioles in Colorado, species by species

SpeciesFirst arrivalsCommon byPeakMost gone byPeak %
Bullock's OrioleApr 22-30May 1-7May 15-21Jul 15-2126%
Orchard OrioleMay 8-14May 8-14May 22-31Jul 8-142.8%
0%10%20%30%Bullock's OrioleOrchard OrioleJanFebMarAprMayJunJulAugSepOctNovDec
  • Bullock's 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 Colorado 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 Colorado

Best counties for Bullock's Oriole

Share of checklists at the peak
  1. Pueblo CountyBest mid May · 1089 checklists that week, 26,547 in all63%
  2. Baca CountyBest mid May · 127 checklists that week, 3,209 in all57%
  3. Washington CountyBest late May · 90 checklists that week, 2,511 in all55%
  4. Prowers CountyBest late June · 182 checklists that week, 11,307 in all55%
  5. Kiowa CountyBest early June · 65 checklists that week, 3,854 in all55%
  6. Adams CountyBest late May · 1578 checklists that week, 44,639 in all52%

Common questions

When do orioles arrive in Colorado?
Bullock's Orioles reach Colorado in late April, are common by early May, peak in mid May (26% of checklists), and most are gone by mid July. They are by far the most reported orioles in Colorado.
When do orioles leave Colorado?
Most Bullock's Orioles have left Colorado by mid 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 Colorado?
The Bullock's Oriole is reported most often in mid May, on about 26% of Colorado checklists.
Which orioles are in Colorado?
Bullock's Oriole and Orchard Oriole are reported regularly; the Bullock's Oriole is the most common.