WhenToBird

Butorides virescens · Ardeidae

When Do Green Herons Arrive in Washington?

Adult male Green Heron
Photo: Jonathan Eisen, CC BY 4.0 via iNaturalist

Green Herons arrive in Washington in the second week of June, peak in early September (2.5% of checklists), and most are gone by early October.

When to look

First arrivalsJun 8-14the second week of June
Common byJun 8-14the second week of June
PeakSep 1-7early September
Most gone byOct 1-7early October

Best: early September. First arrivals the second week of June; most are gone by early October. Peak: on about 2.5% of Washington checklists.

  1. Janrare
  2. Febrare
  3. Marrare
  4. Aprrare
  5. Mayuncommon
  6. Jununcommon
  7. Julcommon
  8. Augpeak season
  9. Seppeak season
  10. Octuncommon
  11. Novrare
  12. Decrare

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

0%1%2%3%Jan 1-7: 0.2% of 41928 checklistsJan 8-14: 0.2% of 31152 checklistsJan 15-21: 0.2% of 31753 checklistsJan 22-31: 0.2% of 42530 checklistsFeb 1-7: 0.2% of 29739 checklistsFeb 8-14: 0.1% of 32746 checklistsFeb 15-21: 0.1% of 40328 checklistsFeb 22-28: 0.2% of 28432 checklistsMar 1-7: 0.1% of 30758 checklistsMar 8-14: 0.1% of 29368 checklistsMar 15-21: 0.1% of 32580 checklistsMar 22-31: 0.1% of 45614 checklistsApr 1-7: 0.1% of 33997 checklistsApr 8-14: 0.1% of 34729 checklistsApr 15-21: 0.2% of 38474 checklistsApr 22-30: 0.3% of 52185 checklistsMay 1-7: 0.4% of 44236 checklistsMay 8-14: 0.5% of 48708 checklistsMay 15-21: 0.5% of 41742 checklistsMay 22-31: 0.6% of 57082 checklistsJun 1-7: 0.7% of 39193 checklistsJun 8-14: 0.8% of 36042 checklistsJun 15-21: 0.8% of 34003 checklistsJun 22-30: 1.0% of 39711 checklistsJul 1-7: 1.1% of 31949 checklistsJul 8-14: 1.2% of 29086 checklistsJul 15-21: 1.3% of 28045 checklistsJul 22-31: 1.8% of 38275 checklistsAug 1-7: 2.0% of 28846 checklistsAug 8-14: 2.0% of 28036 checklistsAug 15-21: 2.0% of 27614 checklistsAug 22-31: 2.6% of 40356 checklistsSep 1-7: 2.6% of 31214 checklistsSep 8-14: 2.1% of 27795 checklistsSep 15-21: 1.8% of 29677 checklistsSep 22-30: 1.4% of 35241 checklistsOct 1-7: 0.8% of 28605 checklistsOct 8-14: 0.4% of 28655 checklistsOct 15-21: 0.2% of 24643 checklistsOct 22-31: 0.2% of 34874 checklistsNov 1-7: 0.1% of 25658 checklistsNov 8-14: 0.1% of 25700 checklistsNov 15-21: 0.1% of 24331 checklistsNov 22-30: 0.1% of 32784 checklistsDec 1-7: 0.1% of 24099 checklistsDec 8-14: 0.1% of 23339 checklistsDec 15-21: 0.1% of 27666 checklistsDec 22-31: 0.1% of 42130 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 Washington 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 Washington

Best counties

Share of checklists at the peak
  1. King CountyBest early September · 7276 checklists that week, 390,864 in all6.4%
  2. Pierce CountyBest late August · 2407 checklists that week, 92,224 in all6.2%
  3. Clark CountyBest early September · 939 checklists that week, 53,250 in all4.9%
  4. Thurston CountyBest late August · 1618 checklists that week, 68,352 in all3.5%
  5. Snohomish CountyBest mid August · 2047 checklists that week, 131,467 in all3.3%
  6. Cowlitz CountyBest mid August · 241 checklists that week, 15,273 in all3.0%

Best spots

Share of checklists at the peak
  1. N Levee Road ParkPierce County, best early August · 108 checklists that week, 1,897 in all71%
  2. Thomas LakeSnohomish County, best late August · 23 checklists that week, 683 in all49%
  3. Union Bay Natural AreaKing County, best the second week of September · 351 checklists that week, 20,611 in all48%

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

Best time of day

In Washington, the Green Heron is most often listed on checklists started between 6 and 8 am (1.2% of those checklists).

0%0.5%1%1.5%2%12 am: too few checklists (796) to judge1 am: too few checklists (776) to judge2 am: too few checklists (709) to judge3 am: too few checklists (901) to judge4 am: too few checklists (3221) to judge5 am: too few checklists (16576) to judge6 am: 1.6% of 56744 checklists7 am: 1.0% of 133294 checklists8 am: 0.7% of 184196 checklists9 am: 0.7% of 186303 checklists10 am: 0.6% of 177063 checklists11 am: 0.6% of 154936 checklists12 pm: 0.5% of 138061 checklists1 pm: 0.4% of 127449 checklists2 pm: 0.5% of 121511 checklists3 pm: 0.4% of 107793 checklists4 pm: 0.6% of 82862 checklists5 pm: 0.7% of 57183 checklists6 pm: 0.9% of 39886 checklists7 pm: too few checklists (26969) to judge8 pm: too few checklists (12427) to judge9 pm: too few checklists (3658) to judge10 pm: too few checklists (1500) to judge11 pm: too few checklists (834) 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%0.2%
February0.2%0.1%0.1%0.2%
March0.1%0.1%0.1%0.1%
April0.1%0.1%0.2%0.3%
May0.4%0.5%0.5%0.6%
June0.7%0.8%0.8%1.0%
July1.1%1.2%1.3%1.8%
August2.0%2.0%2.0%2.6%
September2.6%2.1%1.8%1.4%
October0.8%0.4%0.2%0.2%
November0.1%0.1%0.1%0.1%
December0.1%0.1%0.1%0.1%

Neighboring states

  • Oregon: arrives late April, 6 weeks earlier than Washington
  • Nevada: arrives late March, 10 weeks earlier than Washington
  • California: arrives early March, 13 weeks earlier than Washington
  • Arizona: year-round, peaks late September

Common questions

When do Green Herons arrive in Washington?
Green Herons arrive in Washington in the second week of June, peak in early September (2.5% of checklists), and most are gone by early October.
When do Green Herons leave Washington?
Most Green Herons have left Washington by early October, when reports fall below half their usual rate.
When is the best time to see a Green Heron in Washington?
The Green Heron is reported most often in early September, on about 2.5% of Washington checklists.
Where in Washington are Green Herons seen most often?
By county, King County, Pierce County, and Clark County have the highest peak reporting rates for the Green Heron (counties with at least 200 checklists).