Horned Grebes mostly pass through Iowa: they arrive in the second week of October, peak in early November (4.6% of checklists), and most are gone by early December.
When to look
First arrivalsOct 8-14the second week of October
Common byOct 8-14the second week of October
PeakNov 1-7early November
Most gone byDec 1-7early December
Best: early November. First arrivals the second week of October; most are gone by early December. Peak: on about 4.6% of Iowa checklists.
Jannot usually seen
Febnot usually seen
Maruncommon
Aprcommon
Mayrare
Junnot usually seen
Julnot usually seen
Augnot usually seen
Sepnot usually seen
Octpeak season
Novpeak season
Decuncommon
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 Iowa 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.
Big Creek State ParkPolk County, best early November · 26 checklists that week, 561 in all27%
Lake Manawa State ParkPottawattamie County, best the second week of November · 29 checklists that week, 599 in all25%
Cedar Lake ParkLinn County, best early April · 48 checklists that week, 1,387 in all22%
Busy spots report more of everything; compare the checklist counts before you drive anywhere.
Best time of day
In Iowa, the Horned Grebe is most often listed on checklists started between 12 and 2 pm (0.8% 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%
0.1%
February
0%
0%
0%
0.1%
March
0.1%
0.5%
0.6%
1.7%
April
2.2%
1.9%
1.9%
1.1%
May
0.2%
0.1%
0.1%
0%
June
0%
0%
0%
0%
July
0%
0%
0%
0%
August
0%
0%
0%
0%
September
0.1%
0.1%
0.1%
0.1%
October
0.1%
0.4%
1.5%
4.1%
November
4.7%
5.1%
3.7%
1.6%
December
0.7%
0.2%
0.1%
0.1%
Neighboring states
Missouri: arrives mid October, 1 week later than Iowa
Wisconsin: arrives early October, 1 week earlier than Iowa
Minnesota: arrives late March, 22 weeks later than Iowa
Illinois: arrives late February, 18 weeks later than Iowa
Common questions
When do Horned Grebes arrive in Iowa?
Horned Grebes mostly pass through Iowa: they arrive in the second week of October, peak in early November (4.6% of checklists), and most are gone by early December.
When do Horned Grebes leave Iowa?
Most Horned Grebes have left Iowa by early December, when reports fall below half their usual rate.
When is the best time to see a Horned Grebe in Iowa?
The Horned Grebe is reported most often in early November, on about 4.6% of Iowa checklists.
Where in Iowa are Horned Grebes seen most often?
By county, Marion County, Cerro Gordo County, and Polk County have the highest peak reporting rates for the Horned Grebe (counties with at least 200 checklists).