WhenToBird

Ardea herodias · Ardeidae

When Do Great Blue Herons Arrive in Oregon?

Adult Great Blue Heron
Photo: mostbittern, CC BY 4.0 via iNaturalist

The Great Blue Heron is in Oregon all year. It turns up on about 22% of checklists at its peak (early September) and on 12% in its quietest week (mid June).

When to look

PresentAll year
Peak weekSep 1-7early September
Quietest weekJun 15-21mid June

Best: early September. Here all year. Peak: on about 22% of Oregon checklists.

  1. Jancommon
  2. Febcommon
  3. Marcommon
  4. Aprcommon
  5. Maycommon
  6. Juncommon
  7. Julcommon
  8. Augpeak season
  9. Seppeak season
  10. Octpeak season
  11. Novpeak season
  12. Decpeak season

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

0%10%20%30%Jan 1-7: 17% of 34973 checklistsJan 8-14: 16% of 26807 checklistsJan 15-21: 16% of 26567 checklistsJan 22-31: 17% of 36019 checklistsFeb 1-7: 16% of 24020 checklistsFeb 8-14: 15% of 25765 checklistsFeb 15-21: 14% of 31019 checklistsFeb 22-28: 14% of 24582 checklistsMar 1-7: 14% of 24834 checklistsMar 8-14: 13% of 24642 checklistsMar 15-21: 13% of 27420 checklistsMar 22-31: 13% of 39913 checklistsApr 1-7: 13% of 28817 checklistsApr 8-14: 13% of 31221 checklistsApr 15-21: 14% of 34402 checklistsApr 22-30: 14% of 47144 checklistsMay 1-7: 15% of 37716 checklistsMay 8-14: 15% of 39651 checklistsMay 15-21: 15% of 37496 checklistsMay 22-31: 14% of 56967 checklistsJun 1-7: 12% of 35893 checklistsJun 8-14: 12% of 31880 checklistsJun 15-21: 12% of 30942 checklistsJun 22-30: 12% of 38478 checklistsJul 1-7: 14% of 27409 checklistsJul 8-14: 15% of 25161 checklistsJul 15-21: 15% of 25473 checklistsJul 22-31: 17% of 33920 checklistsAug 1-7: 18% of 24310 checklistsAug 8-14: 19% of 23675 checklistsAug 15-21: 21% of 23623 checklistsAug 22-31: 22% of 33762 checklistsSep 1-7: 23% of 25120 checklistsSep 8-14: 22% of 24458 checklistsSep 15-21: 21% of 25528 checklistsSep 22-30: 21% of 31631 checklistsOct 1-7: 20% of 25498 checklistsOct 8-14: 20% of 25161 checklistsOct 15-21: 19% of 23701 checklistsOct 22-31: 21% of 30996 checklistsNov 1-7: 20% of 21089 checklistsNov 8-14: 20% of 21880 checklistsNov 15-21: 19% of 21501 checklistsNov 22-30: 19% of 28930 checklistsDec 1-7: 18% of 19807 checklistsDec 8-14: 17% of 21022 checklistsDec 15-21: 16% of 24817 checklistsDec 22-31: 16% of 37592 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 Oregon 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 Oregon

Best counties

Share of checklists at the peak
  1. Columbia CountyBest early September · 533 checklists that week, 27,750 in all47%
  2. Washington CountyBest early September · 1836 checklists that week, 110,376 in all45%
  3. Sherman CountyBest early December · 39 checklists that week, 4,629 in all45%
  4. Tillamook CountyBest the second week of September · 937 checklists that week, 45,809 in all38%
  5. Hood River CountyBest early November · 144 checklists that week, 9,695 in all38%
  6. Umatilla CountyBest mid September · 236 checklists that week, 17,651 in all37%

Best spots

Share of checklists at the peak
  1. Fern Ridge Wildlife Area (Coyote Creek)Lane County, best the second week of July · 42 checklists that week, 981 in all99%
  2. Fernhill WetlandsWashington County, best the second week of August · 118 checklists that week, 6,516 in all99%
  3. Bybee LakeMultnomah County, best mid July · 67 checklists that week, 1,688 in all99%
  4. William L. Finley National Wildlife RefugeBenton County, best mid August · 23 checklists that week, 1,760 in all98%
  5. Tualatin River National Wildlife RefugeWashington County, best early July · 125 checklists that week, 5,254 in all98%
  6. West ArmColumbia County, best late August · 55 checklists that week, 312 in all98%

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

Best time of day

In Oregon, the Great Blue Heron is most often listed on checklists started between 8 and 10 am (19% of those checklists).

0%5%10%15%20%12 am: too few checklists (1505) to judge1 am: too few checklists (675) to judge2 am: too few checklists (626) to judge3 am: too few checklists (1641) to judge4 am: too few checklists (3696) to judge5 am: too few checklists (14524) to judge6 am: 15% of 50677 checklists7 am: 17% of 125347 checklists8 am: 18% of 163668 checklists9 am: 19% of 160351 checklists10 am: 18% of 148940 checklists11 am: 17% of 124743 checklists12 pm: 16% of 112537 checklists1 pm: 16% of 98999 checklists2 pm: 16% of 94690 checklists3 pm: 16% of 87923 checklists4 pm: 14% of 75235 checklists5 pm: 13% of 54504 checklists6 pm: 12% of 40469 checklists7 pm: 8.5% of 33675 checklists8 pm: too few checklists (18715) to judge9 pm: too few checklists (5839) to judge10 pm: too few checklists (2704) to judge11 pm: too few checklists (1549) 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
January17%16%16%17%
February16%15%14%14%
March14%13%13%13%
April13%13%14%14%
May15%15%15%14%
June12%12%12%12%
July14%15%15%17%
August18%19%21%22%
September23%22%21%21%
October20%20%19%21%
November20%20%19%19%
December18%17%16%16%

Neighboring states

  • Washington: year-round, peaks early September
  • Idaho: year-round, peaks early September
  • Nevada: all year, most in fall, peaks early September
  • California: year-round, peaks late August

Common questions

When do Great Blue Herons arrive in Oregon?
The Great Blue Heron is in Oregon all year. It turns up on about 22% of checklists at its peak (early September) and on 12% in its quietest week (mid June).
When do Great Blue Herons leave Oregon?
The Great Blue Heron does not leave Oregon: it is reported all year, from 12% of checklists in mid June to 22% in early September.
When is the best time to see a Great Blue Heron in Oregon?
The Great Blue Heron is reported most often in early September, on about 22% of Oregon checklists.
Where in Oregon are Great Blue Herons seen most often?
By county, Columbia County, Washington County, and Sherman County have the highest peak reporting rates for the Great Blue Heron (counties with at least 200 checklists).