WhenToBird

Ardea herodias · Ardeidae

When Do Great Blue Herons Arrive in Alaska?

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

Great Blue Herons are winter birds in Alaska: the first arrive in late June, they are common by mid July, peak in late October (5.6% of checklists), and most are gone by early May.

When to look

First arrivalsJun 22-30late June
Common byJul 15-21mid July
PeakOct 22-31late October
Most gone byMay 1-7early May

Best: late October. First arrivals late June; most are gone by early May. Peak: on about 5.6% of Alaska checklists.

  1. Jancommon
  2. Febcommon
  3. Marcommon
  4. Aprcommon
  5. Mayuncommon
  6. Jununcommon
  7. Juluncommon
  8. Augcommon
  9. Seppeak season
  10. Octpeak season
  11. Novpeak season
  12. Deccommon

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

0%2%4%6%8%Jan 1-7: 3.1% of 3788 checklistsJan 8-14: 3.3% of 2852 checklistsJan 15-21: 3.9% of 2810 checklistsJan 22-31: 2.5% of 3629 checklistsFeb 1-7: 3.8% of 2519 checklistsFeb 8-14: 2.8% of 2927 checklistsFeb 15-21: 3.3% of 3743 checklistsFeb 22-28: 2.6% of 2846 checklistsMar 1-7: 2.8% of 2904 checklistsMar 8-14: 2.4% of 3073 checklistsMar 15-21: 3.7% of 3359 checklistsMar 22-31: 2.8% of 5855 checklistsApr 1-7: 2.4% of 4329 checklistsApr 8-14: 1.9% of 4949 checklistsApr 15-21: 1.9% of 7114 checklistsApr 22-30: 1.9% of 10916 checklistsMay 1-7: 1.7% of 11827 checklistsMay 8-14: 1.6% of 14115 checklistsMay 15-21: 1.3% of 12152 checklistsMay 22-31: 1.0% of 19919 checklistsJun 1-7: 0.8% of 15816 checklistsJun 8-14: 1.0% of 17194 checklistsJun 15-21: 0.8% of 15943 checklistsJun 22-30: 1.1% of 16192 checklistsJul 1-7: 1.2% of 9815 checklistsJul 8-14: 1.3% of 8263 checklistsJul 15-21: 1.9% of 7081 checklistsJul 22-31: 1.9% of 9434 checklistsAug 1-7: 2.6% of 6380 checklistsAug 8-14: 3.0% of 6258 checklistsAug 15-21: 3.6% of 6114 checklistsAug 22-31: 4.3% of 8189 checklistsSep 1-7: 4.5% of 5848 checklistsSep 8-14: 4.4% of 4853 checklistsSep 15-21: 5.3% of 4415 checklistsSep 22-30: 5.2% of 5086 checklistsOct 1-7: 5.2% of 3576 checklistsOct 8-14: 4.5% of 4212 checklistsOct 15-21: 5.2% of 3339 checklistsOct 22-31: 6.3% of 4169 checklistsNov 1-7: 5.2% of 2844 checklistsNov 8-14: 4.4% of 2753 checklistsNov 15-21: 5.0% of 2291 checklistsNov 22-30: 4.4% of 3066 checklistsDec 1-7: 4.4% of 2199 checklistsDec 8-14: 3.6% of 2472 checklistsDec 15-21: 3.2% of 3071 checklistsDec 22-31: 3.8% of 3442 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 Alaska 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 Alaska

Best counties

Share of checklists at the peak
  1. Wrangell City and BoroughBest late August · 38 checklists that week, 2,509 in all32%
  2. Hoonah-Angoon Census AreaBest early October · 91 checklists that week, 8,159 in all29%
  3. Prince of Wales-Hyder Census AreaBest early November · 44 checklists that week, 2,822 in all28%
  4. Ketchikan Gateway BoroughBest late September · 113 checklists that week, 4,641 in all24%
  5. Petersburg BoroughBest late November · 135 checklists that week, 6,063 in all23%
  6. Chugach Census AreaBest the second week of October · 67 checklists that week, 7,540 in all19%

Best spots

Share of checklists at the peak
  1. Starrigavan BaySitka City and Borough, best the second week of September · 22 checklists that week, 883 in all60%
  2. Eagle RiverJuneau City and Borough, best the second week of June · 22 checklists that week, 1,420 in all53%
  3. Kalsin PondKodiak Island Borough, best late March · 33 checklists that week, 798 in all45%
  4. Mendenhall Glacier Ecology National Recreation TrailJuneau City and Borough, best the second week of August · 28 checklists that week, 934 in all35%

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

Best time of day

In Alaska, the Great Blue Heron is most often listed on checklists started between 8 and 10 am (3.0% of those checklists).

0%1%2%3%4%12 am: too few checklists (549) to judge1 am: too few checklists (365) to judge2 am: too few checklists (291) to judge3 am: too few checklists (624) to judge4 am: too few checklists (1241) to judge5 am: too few checklists (3532) to judge6 am: 2.6% of 9751 checklists7 am: 3.0% of 17236 checklists8 am: 2.9% of 24936 checklists9 am: 3.1% of 30139 checklists10 am: 2.6% of 30866 checklists11 am: 2.6% of 28207 checklists12 pm: 2.4% of 25650 checklists1 pm: 2.5% of 24144 checklists2 pm: 2.3% of 23323 checklists3 pm: 2.1% of 20763 checklists4 pm: 1.8% of 18245 checklists5 pm: 2.1% of 14895 checklists6 pm: 1.9% of 11707 checklists7 pm: 1.5% of 9365 checklists8 pm: 1.2% of 6934 checklists9 pm: too few checklists (4176) to judge10 pm: too few checklists (2050) to judge11 pm: too few checklists (952) 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
January3.1%3.3%3.9%2.5%
February3.8%2.8%3.3%2.6%
March2.8%2.4%3.7%2.8%
April2.4%1.9%1.9%1.9%
May1.7%1.6%1.3%1.0%
June0.8%1.0%0.8%1.1%
July1.2%1.3%1.9%1.9%
August2.6%3.0%3.6%4.3%
September4.5%4.4%5.3%5.2%
October5.2%4.5%5.2%6.3%
November5.2%4.4%5.0%4.4%
December4.4%3.6%3.2%3.8%

Neighboring states

  • Washington: year-round, peaks early September
  • Oregon: year-round, peaks early September
  • Idaho: year-round, peaks early September
  • Montana: arrives early April, 11 weeks earlier than Alaska

Common questions

When do Great Blue Herons arrive in Alaska?
Great Blue Herons are winter birds in Alaska: the first arrive in late June, they are common by mid July, peak in late October (5.6% of checklists), and most are gone by early May.
When do Great Blue Herons leave Alaska?
Most Great Blue Herons have left Alaska by early May, when reports fall below half their usual rate. Stragglers are still reported until late May.
When is the best time to see a Great Blue Heron in Alaska?
The Great Blue Heron is reported most often in late October, on about 5.6% of Alaska checklists.
Where in Alaska are Great Blue Herons seen most often?
By county, Wrangell City and Borough, Hoonah-Angoon Census Area, and Prince of Wales-Hyder Census Area have the highest peak reporting rates for the Great Blue Heron (counties with at least 200 checklists).