WhenToBird

Geothlypis philadelphia · Parulidae

When Do Mourning Warblers Arrive in Michigan?

Adult Mourning Warbler
Photo: John Rosford, CC BY 4.0 via iNaturalist

Mourning Warblers mostly pass through Michigan: they arrive in the second week of May, peak in late May (3.1% of checklists), and most are gone by early July.

When to look

First arrivalsMay 8-14the second week of May
Common byMay 8-14the second week of May
PeakMay 22-31late May
Most gone byJul 1-7early July

Best: late May. First arrivals the second week of May; most are gone by early July. Peak: on about 3.1% of Michigan checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marnot usually seen
  4. Aprnot usually seen
  5. Maypeak season
  6. Junpeak season
  7. Juluncommon
  8. Auguncommon
  9. Sepuncommon
  10. Octnot usually seen
  11. Novnot usually seen
  12. Decnot usually seen

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

0%1%2%3%4%Jan 1-7: 0% of 38160 checklistsJan 8-14: 0% of 24696 checklistsJan 15-21: 0% of 23771 checklistsJan 22-31: 0% of 31347 checklistsFeb 1-7: 0% of 23225 checklistsFeb 8-14: 0% of 27398 checklistsFeb 15-21: 0% of 36606 checklistsFeb 22-28: 0% of 27127 checklistsMar 1-7: 0% of 29700 checklistsMar 8-14: 0% of 31587 checklistsMar 15-21: 0% of 32118 checklistsMar 22-31: 0% of 47777 checklistsApr 1-7: 0% of 38557 checklistsApr 8-14: 0% of 42207 checklistsApr 15-21: 0% of 42759 checklistsApr 22-30: 0% of 64458 checklistsMay 1-7: 0.1% of 60998 checklistsMay 8-14: 0.8% of 72091 checklistsMay 15-21: 3.0% of 59058 checklistsMay 22-31: 3.5% of 64724 checklistsJun 1-7: 2.6% of 35990 checklistsJun 8-14: 2.3% of 32595 checklistsJun 15-21: 1.8% of 30017 checklistsJun 22-30: 1.4% of 33988 checklistsJul 1-7: 1.4% of 28708 checklistsJul 8-14: 0.7% of 25175 checklistsJul 15-21: 0.4% of 24084 checklistsJul 22-31: 0.3% of 33522 checklistsAug 1-7: 0.2% of 25098 checklistsAug 8-14: 0.3% of 24353 checklistsAug 15-21: 0.4% of 25059 checklistsAug 22-31: 0.7% of 37489 checklistsSep 1-7: 0.7% of 28410 checklistsSep 8-14: 0.5% of 27887 checklistsSep 15-21: 0.2% of 26614 checklistsSep 22-30: 0.1% of 32557 checklistsOct 1-7: 0.1% of 25844 checklistsOct 8-14: 0% of 27741 checklistsOct 15-21: 0.1% of 24693 checklistsOct 22-31: 0% of 32460 checklistsNov 1-7: 0% of 23660 checklistsNov 8-14: 0% of 21542 checklistsNov 15-21: 0% of 19922 checklistsNov 22-30: 0% of 25069 checklistsDec 1-7: 0% of 18272 checklistsDec 8-14: 0% of 18961 checklistsDec 15-21: 0% of 24171 checklistsDec 22-31: 0% of 30908 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 Michigan 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 Michigan

Best counties

Share of checklists at the peak
  1. Ogemaw CountyBest early June · 147 checklists that week, 4,675 in all26%
  2. Gogebic CountyBest the second week of June · 200 checklists that week, 4,523 in all20%
  3. Ontonagon CountyBest early June · 140 checklists that week, 3,548 in all17%
  4. Arenac CountyBest late May · 271 checklists that week, 4,464 in all13%
  5. Alger CountyBest the second week of June · 537 checklists that week, 16,120 in all12%
  6. Keweenaw CountyBest the second week of June · 407 checklists that week, 12,437 in all12%

Best spots

Share of checklists at the peak
  1. Manistee National Forest (Whiskey Creek)Mason County, best late May · 32 checklists that week, 154 in all71%
  2. Pigeon River Country State Forest AreaOtsego County, best mid June · 24 checklists that week, 455 in all68%
  3. Port Huron State Game AreaSt. Clair County, best early June · 53 checklists that week, 863 in all55%
  4. Sleeping Bear Dunes National Lakeshore (southeast)Leelanau County, best early July · 20 checklists that week, 247 in all49%
  5. Wigwam Bay State Wildlife AreaArenac County, best late May · 56 checklists that week, 327 in all39%

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

Best time of day

In Michigan, the Mourning Warbler is most often listed on checklists started between 6 and 8 am (1.6% of those checklists).

0%1%2%3%12 am: too few checklists (712) to judge1 am: too few checklists (592) to judge2 am: too few checklists (532) to judge3 am: too few checklists (516) to judge4 am: too few checklists (1592) to judge5 am: too few checklists (6849) to judge6 am: 2.3% of 39298 checklists7 am: 1.4% of 120344 checklists8 am: 0.9% of 180109 checklists9 am: 0.7% of 171966 checklists10 am: 0.6% of 156332 checklists11 am: 0.5% of 134964 checklists12 pm: 0.3% of 120967 checklists1 pm: 0.3% of 113852 checklists2 pm: 0.3% of 110773 checklists3 pm: 0.2% of 105530 checklists4 pm: 0.2% of 100958 checklists5 pm: 0.2% of 80085 checklists6 pm: 0.3% of 62883 checklists7 pm: 0.2% of 44912 checklists8 pm: too few checklists (21062) to judge9 pm: too few checklists (5920) to judge10 pm: too few checklists (1629) to judge11 pm: too few checklists (775) 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%0%0%0%
February0%0%0%0%
March0%0%0%0%
April0%0%0%0%
May0.1%0.8%3.0%3.5%
June2.6%2.3%1.8%1.4%
July1.4%0.7%0.4%0.3%
August0.2%0.3%0.4%0.7%
September0.7%0.5%0.2%0.1%
October0.1%0%0.1%0%
November0%0%0%0%
December0%0%0%0%

Neighboring states

  • Ohio: arrives early May, 1 week earlier than Michigan
  • Indiana: arrives the second week of May, in the same week than Michigan
  • Illinois: arrives the second week of May, in the same week than Michigan
  • Wisconsin: arrives the second week of May, in the same week than Michigan

Common questions

When do Mourning Warblers arrive in Michigan?
Mourning Warblers mostly pass through Michigan: they arrive in the second week of May, peak in late May (3.1% of checklists), and most are gone by early July.
When do Mourning Warblers leave Michigan?
Most Mourning Warblers have left Michigan by early July, when reports fall below half their usual rate.
When is the best time to see a Mourning Warbler in Michigan?
The Mourning Warbler is reported most often in late May, on about 3.1% of Michigan checklists.
Where in Michigan are Mourning Warblers seen most often?
By county, Ogemaw County, Gogebic County, and Ontonagon County have the highest peak reporting rates for the Mourning Warbler (counties with at least 200 checklists).