WhenToBird

Sialia currucoides · Turdidae

When Do Mountain Bluebirds Arrive in California?

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

Mountain Bluebirds arrive in California in mid May, peak in late June (1.1% of checklists), and most are gone by late August.

When to look

First arrivalsMay 15-21mid May
Common byMay 15-21mid May
PeakJun 22-30late June
Most gone byAug 22-31late August

Best: late June. First arrivals mid May; most are gone by late August. Peak: on about 1.1% of California checklists.

  1. Janpeak season
  2. Febpeak season
  3. Marcommon
  4. Apruncommon
  5. Maycommon
  6. Junpeak season
  7. Julpeak season
  8. Augcommon
  9. Sepuncommon
  10. Octuncommon
  11. Novpeak season
  12. Decpeak season

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

0%0.5%1%1.5%Jan 1-7: 0.9% of 112336 checklistsJan 8-14: 0.9% of 85518 checklistsJan 15-21: 0.9% of 86488 checklistsJan 22-31: 1.1% of 116174 checklistsFeb 1-7: 0.9% of 75171 checklistsFeb 8-14: 0.7% of 84467 checklistsFeb 15-21: 0.7% of 105683 checklistsFeb 22-28: 0.8% of 83396 checklistsMar 1-7: 0.7% of 77470 checklistsMar 8-14: 0.5% of 75180 checklistsMar 15-21: 0.4% of 80770 checklistsMar 22-31: 0.3% of 114116 checklistsApr 1-7: 0.3% of 84057 checklistsApr 8-14: 0.2% of 83692 checklistsApr 15-21: 0.2% of 89242 checklistsApr 22-30: 0.2% of 114289 checklistsMay 1-7: 0.3% of 85728 checklistsMay 8-14: 0.3% of 91984 checklistsMay 15-21: 0.4% of 75478 checklistsMay 22-31: 0.5% of 106250 checklistsJun 1-7: 0.6% of 70051 checklistsJun 8-14: 0.9% of 67485 checklistsJun 15-21: 1.2% of 66269 checklistsJun 22-30: 1.1% of 79172 checklistsJul 1-7: 0.9% of 62877 checklistsJul 8-14: 0.7% of 60328 checklistsJul 15-21: 0.6% of 59705 checklistsJul 22-31: 0.6% of 83796 checklistsAug 1-7: 0.4% of 60215 checklistsAug 8-14: 0.4% of 60172 checklistsAug 15-21: 0.4% of 59877 checklistsAug 22-31: 0.3% of 89107 checklistsSep 1-7: 0.3% of 72000 checklistsSep 8-14: 0.3% of 71228 checklistsSep 15-21: 0.3% of 76808 checklistsSep 22-30: 0.2% of 100204 checklistsOct 1-7: 0.2% of 76571 checklistsOct 8-14: 0.2% of 80874 checklistsOct 15-21: 0.3% of 74581 checklistsOct 22-31: 0.3% of 97498 checklistsNov 1-7: 0.5% of 70851 checklistsNov 8-14: 0.7% of 72431 checklistsNov 15-21: 0.8% of 66767 checklistsNov 22-30: 0.8% of 94737 checklistsDec 1-7: 0.9% of 65393 checklistsDec 8-14: 0.8% of 67449 checklistsDec 15-21: 0.9% of 83421 checklistsDec 22-31: 0.7% of 124993 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 California 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 California

Best counties

Share of checklists at the peak
  1. Sierra CountyBest the second week of April · 74 checklists that week, 8,945 in all17%
  2. Modoc CountyBest the second week of October · 76 checklists that week, 6,138 in all13%
  3. Inyo CountyBest early July · 561 checklists that week, 35,713 in all12%
  4. Alpine CountyBest early July · 274 checklists that week, 6,013 in all12%
  5. Mono CountyBest mid June · 2928 checklists that week, 38,666 in all11%
  6. Lassen CountyBest early June · 271 checklists that week, 8,378 in all8.1%

Best spots

Share of checklists at the peak
  1. Schulman GroveInyo County, best late June · 40 checklists that week, 519 in all89%
  2. Kyburz FlatSierra County, best late June · 31 checklists that week, 285 in all84%
  3. Ravenswood Open Space PreserveSan Mateo County, best late January · 44 checklists that week, 321 in all81%
  4. Bodie Bowl Area of Critical Environmental ConcernMono County, best mid September · 22 checklists that week, 233 in all75%
  5. Inyo National Forest (north 2)Mono County, best mid June · 22 checklists that week, 109 in all74%

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

Best time of day

In California, the Mountain Bluebird is most often listed on checklists started between 12 and 2 pm (0.7% of those checklists).

0%0.5%1%12 am: too few checklists (1688) to judge1 am: too few checklists (1451) to judge2 am: too few checklists (1402) to judge3 am: too few checklists (1743) to judge4 am: too few checklists (4647) to judge5 am: too few checklists (32158) to judge6 am: 0.5% of 186053 checklists7 am: 0.5% of 444086 checklists8 am: 0.5% of 535846 checklists9 am: 0.6% of 486061 checklists10 am: 0.6% of 411130 checklists11 am: 0.7% of 325798 checklists12 pm: 0.7% of 269132 checklists1 pm: 0.7% of 244762 checklists2 pm: 0.7% of 235420 checklists3 pm: 0.6% of 232365 checklists4 pm: 0.4% of 208688 checklists5 pm: 0.3% of 146104 checklists6 pm: 0.3% of 96867 checklists7 pm: too few checklists (50942) to judge8 pm: too few checklists (14803) to judge9 pm: too few checklists (5561) to judge10 pm: too few checklists (3546) to judge11 pm: too few checklists (2092) 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
January0.9%0.9%0.9%1.1%
February0.9%0.7%0.7%0.8%
March0.7%0.5%0.4%0.3%
April0.3%0.2%0.2%0.2%
May0.3%0.3%0.4%0.5%
June0.6%0.9%1.2%1.1%
July0.9%0.7%0.6%0.6%
August0.4%0.4%0.4%0.3%
September0.3%0.3%0.3%0.2%
October0.2%0.2%0.3%0.3%
November0.5%0.7%0.8%0.8%
December0.9%0.8%0.9%0.7%

Neighboring states

  • Nevada: arrives the second week of May, 1 week earlier than California
  • Utah: arrives late February, 11 weeks earlier than California
  • Arizona: arrives mid August, 12 weeks later than California
  • Oregon: arrives early March, 10 weeks earlier than California

Common questions

When do Mountain Bluebirds arrive in California?
Mountain Bluebirds arrive in California in mid May, peak in late June (1.1% of checklists), and most are gone by late August.
When do Mountain Bluebirds leave California?
Most Mountain Bluebirds have left California by late August, when reports fall below half their usual rate.
When is the best time to see a Mountain Bluebird in California?
The Mountain Bluebird is reported most often in late June, on about 1.1% of California checklists.
Where in California are Mountain Bluebirds seen most often?
By county, Sierra County, Modoc County, and Inyo County have the highest peak reporting rates for the Mountain Bluebird (counties with at least 200 checklists).