WhenToBird

Nyctanassa violacea · Ardeidae

When Do Yellow-crowned Night Herons Arrive in California?

Adult Yellow-crowned Night-Heron
Photo: Michelle W. （鍾偉瑋）, CC BY 4.0 via iNaturalist

Yellow-crowned Night Herons arrive in California in late April, peak in the second week of August (1.1% of checklists), and most are gone by the second week of March.

When to look

First arrivalsApr 22-30late April
Common byApr 22-30late April
PeakAug 8-14the second week of August
Most gone byMar 8-14the second week of March

Best: the second week of August. First arrivals late April; most are gone by the second week of March. Peak: on about 1.1% of California checklists.

  1. Jancommon
  2. Febcommon
  3. Marcommon
  4. Apruncommon
  5. Mayuncommon
  6. Juncommon
  7. Julpeak season
  8. Augpeak season
  9. Seppeak season
  10. Octcommon
  11. Novcommon
  12. Deccommon

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

0%0.5%1%1.5%Jan 1-7: 0.6% of 112336 checklistsJan 8-14: 0.6% of 85518 checklistsJan 15-21: 0.5% of 86488 checklistsJan 22-31: 0.5% of 116174 checklistsFeb 1-7: 0.4% of 75171 checklistsFeb 8-14: 0.4% of 84467 checklistsFeb 15-21: 0.4% of 105683 checklistsFeb 22-28: 0.6% of 83396 checklistsMar 1-7: 0.4% of 77470 checklistsMar 8-14: 0.3% of 75180 checklistsMar 15-21: 0.3% of 80770 checklistsMar 22-31: 0.2% 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: 0.3% of 114289 checklistsMay 1-7: 0.4% of 85728 checklistsMay 8-14: 0.4% of 91984 checklistsMay 15-21: 0.4% of 75478 checklistsMay 22-31: 0.4% of 106250 checklistsJun 1-7: 0.4% of 70051 checklistsJun 8-14: 0.5% of 67485 checklistsJun 15-21: 0.6% of 66269 checklistsJun 22-30: 0.7% of 79172 checklistsJul 1-7: 0.7% of 62877 checklistsJul 8-14: 1.0% of 60328 checklistsJul 15-21: 0.8% of 59705 checklistsJul 22-31: 1.0% of 83796 checklistsAug 1-7: 1.1% of 60215 checklistsAug 8-14: 1.1% of 60172 checklistsAug 15-21: 1.1% of 59877 checklistsAug 22-31: 1.0% of 89107 checklistsSep 1-7: 0.9% of 72000 checklistsSep 8-14: 0.8% of 71228 checklistsSep 15-21: 0.6% of 76808 checklistsSep 22-30: 0.6% of 100204 checklistsOct 1-7: 0.5% of 76571 checklistsOct 8-14: 0.6% of 80874 checklistsOct 15-21: 0.6% of 74581 checklistsOct 22-31: 0.6% of 97498 checklistsNov 1-7: 0.6% of 70851 checklistsNov 8-14: 0.6% of 72431 checklistsNov 15-21: 0.5% of 66767 checklistsNov 22-30: 0.6% of 94737 checklistsDec 1-7: 0.6% of 65393 checklistsDec 8-14: 0.6% of 67449 checklistsDec 15-21: 0.4% of 83421 checklistsDec 22-31: 0.6% 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. Ventura CountyBest mid November · 1404 checklists that week, 94,391 in all6.3%
  2. San Diego CountyBest mid July · 5490 checklists that week, 405,465 in all5.7%
  3. Santa Barbara CountyBest mid August · 1734 checklists that week, 120,616 in all3.8%
  4. Orange CountyBest the second week of August · 3566 checklists that week, 244,559 in all3.5%
  5. Los Angeles CountyBest mid August · 6078 checklists that week, 410,235 in all2.0%
  6. Marin CountyBest mid January · 2988 checklists that week, 135,728 in all1.4%

Best spots

Share of checklists at the peak
  1. Richardson BayMarin County, best the second week of January · 26 checklists that week, 220 in all93%
  2. Imperial Beach Sports ParkSan Diego County, best early March · 23 checklists that week, 195 in all92%
  3. Tijuana Slough National Wildlife RefugeSan Diego County, best mid July · 38 checklists that week, 3,134 in all90%
  4. Anaheim BayOrange County, best the second week of December · 42 checklists that week, 209 in all82%
  5. Stillwater CoveMonterey County, best the second week of December · 29 checklists that week, 391 in all82%
  6. Santa Clara RiverVentura County, best early November · 118 checklists that week, 5,820 in all74%

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

Best time of day

In California, the Yellow-crowned Night Heron is most often listed on checklists started between 6 and 8 am (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: 0.7% of 186053 checklists7 am: 0.6% of 444086 checklists8 am: 0.6% of 535846 checklists9 am: 0.6% of 486061 checklists10 am: 0.6% of 411130 checklists11 am: 0.5% of 325798 checklists12 pm: 0.4% of 269132 checklists1 pm: 0.5% of 244762 checklists2 pm: 0.5% of 235420 checklists3 pm: 0.6% of 232365 checklists4 pm: 0.5% of 208688 checklists5 pm: 0.6% of 146104 checklists6 pm: 0.5% 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
January0.6%0.6%0.5%0.5%
February0.4%0.4%0.4%0.6%
March0.4%0.3%0.3%0.2%
April0.3%0.2%0.2%0.3%
May0.4%0.4%0.4%0.4%
June0.4%0.5%0.6%0.7%
July0.7%1.0%0.8%1.0%
August1.1%1.1%1.1%1.0%
September0.9%0.8%0.6%0.6%
October0.5%0.6%0.6%0.6%
November0.6%0.6%0.5%0.6%
December0.6%0.6%0.4%0.6%

Neighboring states

  • Oklahoma: arrives the second week of April, 2 weeks earlier than California
  • Kansas: arrives early May, 1 week later than California
  • Texas: arrives the second week of March, 6 weeks earlier than California
  • Louisiana: arrives the second week of March, 6 weeks earlier than California

Common questions

When do Yellow-crowned Night Herons arrive in California?
Yellow-crowned Night Herons arrive in California in late April, peak in the second week of August (1.1% of checklists), and most are gone by the second week of March.
When do Yellow-crowned Night Herons leave California?
Most Yellow-crowned Night Herons have left California by the second week of March, when reports fall below half their usual rate.
When is the best time to see a Yellow-crowned Night Heron in California?
The Yellow-crowned Night Heron is reported most often in the second week of August, on about 1.1% of California checklists.
Where in California are Yellow-crowned Night Herons seen most often?
By county, Ventura County, San Diego County, and Santa Barbara County have the highest peak reporting rates for the Yellow-crowned Night Heron (counties with at least 200 checklists).