Barn Swallows reach Illinois in the second week of April, are common by mid April, peak in the second week of August (42% of checklists), and most are gone by early September.
When to look
First arrivalsApr 8-14the second week of April
Common byApr 15-21mid April
PeakAug 8-14the second week of August
Most gone bySep 1-7early September
Best: the second week of August. First arrivals the second week of April; most are gone by early September. Peak: on about 42% of Illinois checklists.
Jannot usually seen
Febnot usually seen
Marnot usually seen
Aprcommon
Maypeak season
Juncommon
Julpeak season
Augpeak season
Sepcommon
Octrare
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 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.
Busy spots report more of everything; compare the checklist counts before you drive anywhere.
Best time of day
In Illinois, the Barn Swallow is most often listed on checklists started between 6 and 8 am (19% 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%
0.1%
0.1%
0.4%
April
2.1%
6.8%
14%
23%
May
29%
31%
35%
35%
June
27%
27%
28%
29%
July
34%
38%
39%
41%
August
42%
42%
42%
32%
September
20%
10%
3.8%
2.3%
October
1.4%
1.4%
1.2%
0.3%
November
0.1%
0.1%
0.1%
0.1%
December
0.1%
0%
0%
0%
Neighboring states
Indiana: arrives early April, 1 week earlier than Illinois
Wisconsin: arrives the second week of April, in the same week than Illinois
Michigan: arrives the second week of April, in the same week than Illinois
Iowa: arrives the second week of April, in the same week than Illinois
Common questions
When do Barn Swallows arrive in Illinois?
Barn Swallows reach Illinois in the second week of April, are common by mid April, peak in the second week of August (42% of checklists), and most are gone by early September.
When do Barn Swallows leave Illinois?
Most Barn Swallows have left Illinois by early September, when reports fall below half their usual rate. Stragglers are still reported until mid September.
When is the best time to see a Barn Swallow in Illinois?
The Barn Swallow is reported most often in the second week of August, on about 42% of Illinois checklists.
Where in Illinois are Barn Swallows seen most often?
By county, Edwards County, Putnam County, and Greene County have the highest peak reporting rates for the Barn Swallow (counties with at least 200 checklists).