Franklin's Gulls mostly pass through Illinois: they arrive in late September, peak in mid October (1.1% of checklists), and most are gone by the second week of November.
When to look
First arrivalsSep 22-30late September
Common bySep 22-30late September
PeakOct 15-21mid October
Most gone byNov 8-14the second week of November
Best: mid October. First arrivals late September; most are gone by the second week of November. Peak: on about 1.1% of Illinois checklists.
Jannot usually seen
Febnot usually seen
Marnot usually seen
Aprrare
Mayrare
Junrare
Julrare
Auguncommon
Sepcommon
Octpeak season
Novpeak season
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 Illinois 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.
East Fork LakeRichland County, best early September · 30 checklists that week, 192 in all50%
Carlyle LakeClinton County, best late October · 37 checklists that week, 912 in all49%
Horshoe Lake State ParkMadison County, best late October · 93 checklists that week, 3,683 in all36%
Center ParkSangamon County, best late September · 27 checklists that week, 715 in all28%
Busy spots report more of everything; compare the checklist counts before you drive anywhere.
Best time of day
In Illinois, the Franklin's Gull is most often listed on checklists started between 3 and 5 pm (0.2% 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%
0.1%
0.1%
0.1%
February
0.1%
0.1%
0%
0.1%
March
0%
0%
0.1%
0.1%
April
0.1%
0.1%
0.1%
0.1%
May
0.1%
0.1%
0.1%
0.2%
June
0.1%
0.1%
0.1%
0.1%
July
0.1%
0.1%
0.1%
0.1%
August
0.1%
0.1%
0.1%
0.2%
September
0.3%
0.2%
0.2%
0.6%
October
0.7%
1.1%
0.9%
1.2%
November
0.8%
0.7%
0.3%
0.1%
December
0.1%
0.1%
0%
0%
Neighboring states
Indiana: arrives late September, in the same week than Illinois
Iowa: arrives mid July, 9 weeks earlier than Illinois
Missouri: arrives mid September, 1 week earlier than Illinois
Minnesota: arrives mid July, 9 weeks earlier than Illinois
Common questions
When do Franklin's Gulls arrive in Illinois?
Franklin's Gulls mostly pass through Illinois: they arrive in late September, peak in mid October (1.1% of checklists), and most are gone by the second week of November.
When do Franklin's Gulls leave Illinois?
Most Franklin's Gulls have left Illinois by the second week of November, when reports fall below half their usual rate.
When is the best time to see a Franklin's Gull in Illinois?
The Franklin's Gull is reported most often in mid October, on about 1.1% of Illinois checklists.
Where in Illinois are Franklin's Gulls seen most often?
By county, Richland County, Clinton County, and Putnam County have the highest peak reporting rates for the Franklin's Gull (counties with at least 200 checklists).