Purple Martins arrive in Michigan in mid April, peak in late July (7.4% of checklists), and most are gone by late August.
When to look
First arrivalsApr 15-21mid April
Common byApr 15-21mid April
PeakJul 22-31late July
Most gone byAug 22-31late August
Best: late July. First arrivals mid April; most are gone by late August. Peak: on about 7.4% of Michigan checklists.
Jannot usually seen
Febnot usually seen
Marnot usually seen
Apruncommon
Maycommon
Juncommon
Julpeak season
Augpeak season
Sepuncommon
Octnot usually seen
Novnot usually seen
Decnot usually seen
Darker months: more checklists report it. Outlined: peak month.
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
0%few checklistsno data
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.
Monroe CountyBest the second week of August · 499 checklists that week, 22,078 in all47%
Bay CountyBest mid July · 313 checklists that week, 16,522 in all41%
Branch CountyBest late May · 61 checklists that week, 2,279 in all26%
Hillsdale CountyBest late July · 245 checklists that week, 9,510 in all25%
Arenac CountyBest late July · 136 checklists that week, 4,464 in all24%
St. Joseph CountyBest early August · 87 checklists that week, 6,972 in all23%
Best spots
Share of checklists at the peak
Grand RiverOttawa County, best the second week of July · 26 checklists that week, 1,355 in all100%
Tobico LagoonBay County, best the second week of July · 63 checklists that week, 2,390 in all81%
Erie Marsh PreserveMonroe County, best early August · 67 checklists that week, 2,408 in all79%
Whiteford Township ParkMonroe County, best early August · 26 checklists that week, 1,372 in all74%
Busy spots report more of everything; compare the checklist counts before you drive anywhere.
Best time of day
In Michigan, the Purple Martin is most often listed on checklists started between 6 and 8 am (2.7% of those checklists).
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
Month
Days 1-7
8-14
15-21
22-end
January
0%
0%
0%
0%
February
0%
0%
0%
0%
March
0%
0%
0.1%
0.1%
April
0.2%
0.6%
1.9%
2.8%
May
3.2%
3.4%
3.8%
3.6%
June
3.5%
3.1%
3.3%
3.4%
July
4.0%
4.7%
6.2%
7.9%
August
7.9%
6.2%
5.0%
2.8%
September
0.9%
0.3%
0.1%
0.1%
October
0%
0%
0%
0%
November
0%
0%
0%
0%
December
0%
0%
0%
0%
Neighboring states
Ohio: arrives late March, 3 weeks earlier than Michigan
Indiana: arrives late March, 3 weeks earlier than Michigan
Illinois: arrives early April, 2 weeks earlier than Michigan
Wisconsin: arrives the second week of April, 1 week earlier than Michigan
Common questions
When do Purple Martins arrive in Michigan?
Purple Martins arrive in Michigan in mid April, peak in late July (7.4% of checklists), and most are gone by late August.
When do Purple Martins leave Michigan?
Most Purple Martins have left Michigan by late August, when reports fall below half their usual rate. Stragglers are still reported until early September.
When is the best time to see a Purple Martin in Michigan?
The Purple Martin is reported most often in late July, on about 7.4% of Michigan checklists.
Where in Michigan are Purple Martins seen most often?
By county, Monroe County, Bay County, and Branch County have the highest peak reporting rates for the Purple Martin (counties with at least 200 checklists).