WhenToBird

Spizella breweri · Passerellidae

When Do Brewer's Sparrows Arrive in California?

Adult Brewer's Sparrow
Photo: Daughter Dad, CC BY 4.0 via iNaturalist

Brewer's Sparrows arrive in California in the second week of March, peak in mid June (1.2% of checklists), and most are gone by the second week of October.

When to look

First arrivalsMar 8-14the second week of March
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 the second week of March; most are gone by the second week of October. Peak: on about 1.2% of California checklists.

  1. Janrare
  2. Febuncommon
  3. Marcommon
  4. Aprcommon
  5. Maycommon
  6. Junpeak season
  7. Julpeak season
  8. Augcommon
  9. Seppeak season
  10. Octcommon
  11. Novuncommon
  12. Decuncommon

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

0%0.5%1%1.5%Jan 1-7: 0.2% of 112336 checklistsJan 8-14: 0.2% of 85518 checklistsJan 15-21: 0.2% of 86488 checklistsJan 22-31: 0.1% of 116174 checklistsFeb 1-7: 0.2% of 75171 checklistsFeb 8-14: 0.2% of 84467 checklistsFeb 15-21: 0.2% of 105683 checklistsFeb 22-28: 0.3% of 83396 checklistsMar 1-7: 0.3% of 77470 checklistsMar 8-14: 0.4% of 75180 checklistsMar 15-21: 0.5% of 80770 checklistsMar 22-31: 0.6% of 114116 checklistsApr 1-7: 0.7% of 84057 checklistsApr 8-14: 0.7% of 83692 checklistsApr 15-21: 0.8% of 89242 checklistsApr 22-30: 0.7% of 114289 checklistsMay 1-7: 0.6% of 85728 checklistsMay 8-14: 0.5% of 91984 checklistsMay 15-21: 0.5% of 75478 checklistsMay 22-31: 0.7% of 106250 checklistsJun 1-7: 0.9% of 70051 checklistsJun 8-14: 1.1% of 67485 checklistsJun 15-21: 1.4% of 66269 checklistsJun 22-30: 1.1% of 79172 checklistsJul 1-7: 0.8% of 62877 checklistsJul 8-14: 0.7% of 60328 checklistsJul 15-21: 0.5% of 59705 checklistsJul 22-31: 0.6% of 83796 checklistsAug 1-7: 0.5% of 60215 checklistsAug 8-14: 0.6% of 60172 checklistsAug 15-21: 0.6% of 59877 checklistsAug 22-31: 0.7% of 89107 checklistsSep 1-7: 0.8% of 72000 checklistsSep 8-14: 0.9% of 71228 checklistsSep 15-21: 0.9% of 76808 checklistsSep 22-30: 0.9% of 100204 checklistsOct 1-7: 0.7% of 76571 checklistsOct 8-14: 0.4% of 80874 checklistsOct 15-21: 0.3% of 74581 checklistsOct 22-31: 0.3% of 97498 checklistsNov 1-7: 0.2% of 70851 checklistsNov 8-14: 0.3% of 72431 checklistsNov 15-21: 0.2% of 66767 checklistsNov 22-30: 0.2% of 94737 checklistsDec 1-7: 0.2% of 65393 checklistsDec 8-14: 0.2% of 67449 checklistsDec 15-21: 0.2% of 83421 checklistsDec 22-31: 0.2% 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.

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Where in California

Best counties

Share of checklists at the peak
  1. Mono CountyBest the second week of June · 1432 checklists that week, 38,666 in all20%
  2. Modoc CountyBest early September · 236 checklists that week, 6,138 in all18%
  3. Plumas CountyBest the second week of June · 1166 checklists that week, 24,629 in all13%
  4. Inyo CountyBest early September · 503 checklists that week, 35,713 in all11%
  5. Alpine CountyBest mid June · 270 checklists that week, 6,013 in all11%
  6. Sierra CountyBest mid May · 232 checklists that week, 8,945 in all7.2%

Best spots

Share of checklists at the peak
  1. Sierra Valley PreservePlumas County, best early June · 23 checklists that week, 331 in all72%
  2. Mono Basin National Scenic AreaMono County, best late June · 86 checklists that week, 1,309 in all69%
  3. Rush CreekMono County, best mid June · 20 checklists that week, 316 in all66%
  4. Minaret Summit (southeast)Mono County, best late June · 21 checklists that week, 104 in all62%
  5. Bodie Bowl Area of Critical Environmental ConcernMono County, best late June · 20 checklists that week, 233 in all60%

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

Best time of day

In California, the Brewer's Sparrow is most often listed on checklists started between 6 and 8 am (0.8% of those checklists).

0%0.5%1%1.5%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: 1.1% of 186053 checklists7 am: 0.7% of 444086 checklists8 am: 0.6% of 535846 checklists9 am: 0.5% of 486061 checklists10 am: 0.4% of 411130 checklists11 am: 0.4% of 325798 checklists12 pm: 0.4% of 269132 checklists1 pm: 0.4% of 244762 checklists2 pm: 0.3% of 235420 checklists3 pm: 0.3% of 232365 checklists4 pm: 0.4% of 208688 checklists5 pm: 0.4% of 146104 checklists6 pm: 0.4% 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
January0.2%0.2%0.2%0.1%
February0.2%0.2%0.2%0.3%
March0.3%0.4%0.5%0.6%
April0.7%0.7%0.8%0.7%
May0.6%0.5%0.5%0.7%
June0.9%1.1%1.4%1.1%
July0.8%0.7%0.5%0.6%
August0.5%0.6%0.6%0.7%
September0.8%0.9%0.9%0.9%
October0.7%0.4%0.3%0.3%
November0.2%0.3%0.2%0.2%
December0.2%0.2%0.2%0.2%

Neighboring states

  • Nevada: arrives mid March, 1 week later than California
  • Utah: arrives mid April, 5 weeks later than California
  • Arizona: arrives mid August, 21 weeks later than California
  • Oregon: arrives the second week of May, 8 weeks later than California

Common questions

When do Brewer's Sparrows arrive in California?
Brewer's Sparrows arrive in California in the second week of March, peak in mid June (1.2% of checklists), and most are gone by the second week of October.
When do Brewer's Sparrows leave California?
Most Brewer's Sparrows have left California by the second week of October, when reports fall below half their usual rate.
When is the best time to see a Brewer's Sparrow in California?
The Brewer's Sparrow is reported most often in mid June, on about 1.2% of California checklists.
Where in California are Brewer's Sparrows seen most often?
By county, Mono County, Modoc County, and Plumas County have the highest peak reporting rates for the Brewer's Sparrow (counties with at least 200 checklists).