WhenToBird

Sialia currucoides · Turdidae

When Do Mountain Bluebirds Arrive in Wyoming?

Adult male Mountain Bluebird
Photo: Josiah Londerée, CC BY 4.0 via iNaturalist

Mountain Bluebirds reach Wyoming in late February, are common by the second week of March, peak in mid June (13% of checklists), and most are gone by the second week of October.

When to look

First arrivalsFeb 22-28late February
Common byMar 8-14the second week of March
PeakJun 15-21mid June
Most gone byOct 8-14the second week of October

Best: mid June. First arrivals late February; most are gone by the second week of October. Peak: on about 13% of Wyoming checklists.

  1. Jannot usually seen
  2. Febrare
  3. Marpeak season
  4. Aprpeak season
  5. Maypeak season
  6. Junpeak season
  7. Julpeak season
  8. Augcommon
  9. Sepcommon
  10. Octcommon
  11. Novrare
  12. Decnot usually seen

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

0%5%10%15%Jan 1-7: 0.1% of 2543 checklistsJan 8-14: 0.1% of 2114 checklistsJan 15-21: 0% of 1984 checklistsJan 22-31: 0.1% of 2605 checklistsFeb 1-7: 0% of 1940 checklistsFeb 8-14: 0.1% of 1954 checklistsFeb 15-21: 0.2% of 2575 checklistsFeb 22-28: 0.5% of 1932 checklistsMar 1-7: 4.1% of 2486 checklistsMar 8-14: 6.4% of 2535 checklistsMar 15-21: 8.4% of 2726 checklistsMar 22-31: 10% of 4349 checklistsApr 1-7: 10% of 3300 checklistsApr 8-14: 11% of 3500 checklistsApr 15-21: 9.8% of 3701 checklistsApr 22-30: 8.9% of 5887 checklistsMay 1-7: 10% of 5341 checklistsMay 8-14: 9.6% of 6910 checklistsMay 15-21: 9.8% of 6884 checklistsMay 22-31: 11% of 10652 checklistsJun 1-7: 12% of 6807 checklistsJun 8-14: 13% of 6714 checklistsJun 15-21: 12% of 6708 checklistsJun 22-30: 13% of 8160 checklistsJul 1-7: 11% of 5755 checklistsJul 8-14: 11% of 5379 checklistsJul 15-21: 11% of 5299 checklistsJul 22-31: 9.0% of 6830 checklistsAug 1-7: 7.9% of 4581 checklistsAug 8-14: 7.8% of 4625 checklistsAug 15-21: 7.2% of 4466 checklistsAug 22-31: 6.3% of 6562 checklistsSep 1-7: 8.1% of 4543 checklistsSep 8-14: 8.0% of 4652 checklistsSep 15-21: 9.3% of 4186 checklistsSep 22-30: 9.2% of 5301 checklistsOct 1-7: 7.4% of 3248 checklistsOct 8-14: 5.7% of 3010 checklistsOct 15-21: 3.1% of 2624 checklistsOct 22-31: 0.8% of 3170 checklistsNov 1-7: 0.5% of 2110 checklistsNov 8-14: 0.3% of 2153 checklistsNov 15-21: 0.1% of 1971 checklistsNov 22-30: 0% of 2136 checklistsDec 1-7: 0.1% of 1646 checklistsDec 8-14: 0% of 1609 checklistsDec 15-21: 0% of 1954 checklistsDec 22-31: 0.1% of 2392 checklistsJanFebMarAprMayJunJulAugSepOctNovDec
Share of complete checklists reporting it, by week (4 per month). Grey bars: fewer than 10 checklists, not counted.

Frequency is the share of complete checklists in Wyoming 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.

JanFebMarAprMayJunJulAugSepOctNovDec
today
Second week of November

Each county is shaded by the share of complete checklists there that listed the bird, blended with the weeks either side. Darker is more often. It follows where people watch birds, not how many birds there are. How to read it.

Embed this map on your site

Where in Wyoming

Best counties

Share of checklists at the peak
  1. Sublette CountyBest the second week of April · 157 checklists that week, 6,738 in all35%
  2. Weston CountyBest early April · 32 checklists that week, 2,297 in all25%
  3. Crook CountyBest the second week of April · 43 checklists that week, 3,915 in all23%
  4. Teton CountyBest late April · 568 checklists that week, 34,686 in all22%
  5. Big Horn CountyBest mid June · 103 checklists that week, 2,023 in all19%
  6. Park CountyBest early April · 270 checklists that week, 27,277 in all18%

Best spots

Share of checklists at the peak
  1. Old Faithful GeyserTeton County, best early May · 28 checklists that week, 1,258 in all68%
  2. Grand Teton National Park (southwest 3)Teton County, best late May · 25 checklists that week, 373 in all63%
  3. Kelly Warm SpringTeton County, best late March · 20 checklists that week, 167 in all61%
  4. Grand Teton National Park (southwest 4)Teton County, best the second week of June · 21 checklists that week, 251 in all57%
  5. Yellowstone National ParkPark County, best late June · 40 checklists that week, 1,028 in all55%

Busy spots report more of everything; compare the checklist counts before you drive anywhere.

Best time of day

In Wyoming, the Mountain Bluebird is most often listed on checklists started between 6 and 8 am (8.9% of those checklists).

0%5%10%12 am: too few checklists (59) to judge1 am: too few checklists (76) to judge2 am: too few checklists (86) to judge3 am: too few checklists (79) to judge4 am: too few checklists (326) to judge5 am: too few checklists (2271) to judge6 am: 9.0% of 8808 checklists7 am: 8.9% of 18458 checklists8 am: 8.9% of 22143 checklists9 am: 8.1% of 21499 checklists10 am: 7.7% of 19425 checklists11 am: 7.0% of 16017 checklists12 pm: 6.7% of 13868 checklists1 pm: 6.5% of 12984 checklists2 pm: 6.3% of 12605 checklists3 pm: 6.6% of 11821 checklists4 pm: 7.3% of 10571 checklists5 pm: 8.1% of 8746 checklists6 pm: 8.7% of 6707 checklists7 pm: 9.1% of 4890 checklists8 pm: too few checklists (2323) to judge9 pm: too few checklists (554) to judge10 pm: too few checklists (134) to judge11 pm: too few checklists (59) to judge12a3a6a9a12p3p6p9p
Share of checklists started in each local hour that reported it. It reflects when people go birding as well as when birds are active. Grey hours have too few checklists (under 2% of the state’s, or under 200) to judge.
Week-by-week table
MonthDays 1-78-1415-2122-end
January0.1%0.1%0%0.1%
February0%0.1%0.2%0.5%
March4.1%6.4%8.4%10%
April10%11%9.8%8.9%
May10%9.6%9.8%11%
June12%13%12%13%
July11%11%11%9.0%
August7.9%7.8%7.2%6.3%
September8.1%8.0%9.3%9.2%
October7.4%5.7%3.1%0.8%
November0.5%0.3%0.1%0%
December0.1%0%0%0.1%

Neighboring states

  • Colorado: arrives late February, in the same week than Wyoming
  • Utah: arrives late February, in the same week than Wyoming
  • Montana: arrives early March, 1 week later than Wyoming
  • Idaho: arrives the second week of March, 2 weeks later than Wyoming

Common questions

When do Mountain Bluebirds arrive in Wyoming?
Mountain Bluebirds reach Wyoming in late February, are common by the second week of March, peak in mid June (13% of checklists), and most are gone by the second week of October.
When do Mountain Bluebirds leave Wyoming?
Most Mountain Bluebirds have left Wyoming by the second week of October, when reports fall below half their usual rate. Stragglers are still reported until late October.
When is the best time to see a Mountain Bluebird in Wyoming?
The Mountain Bluebird is reported most often in mid June, on about 13% of Wyoming checklists.
Where in Wyoming are Mountain Bluebirds seen most often?
By county, Sublette County, Weston County, and Crook County have the highest peak reporting rates for the Mountain Bluebird (counties with at least 200 checklists).