Clay-colored Sparrows mostly pass through Illinois: they arrive in mid April, peak in the second week of May (1.5% of checklists), and most are gone by the second week of July.
When to look
First arrivalsApr 15-21mid April
Common byApr 15-21mid April
PeakMay 8-14the second week of May
Most gone byJul 8-14the second week of July
Best: the second week of May. First arrivals mid April; most are gone by the second week of July. Peak: on about 1.5% of Illinois checklists.
Jannot usually seen
Febnot usually seen
Marnot usually seen
Aprcommon
Maypeak season
Jununcommon
Julrare
Augrare
Sepuncommon
Octcommon
Novrare
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.
Middle Rock River FeeLee County, best the second week of May · 29 checklists that week, 558 in all14%
Springbrook PrairieDuPage County, best early June · 121 checklists that week, 4,299 in all14%
Busy spots report more of everything; compare the checklist counts before you drive anywhere.
Best time of day
In Illinois, the Clay-colored Sparrow is most often listed on checklists started between 6 and 8 am (0.6% 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%
0%
April
0%
0.1%
0.1%
0.7%
May
1.7%
1.6%
1.0%
0.4%
June
0.2%
0.2%
0.3%
0.2%
July
0.2%
0.2%
0.1%
0.1%
August
0.1%
0.1%
0%
0.1%
September
0.2%
0.2%
0.3%
0.6%
October
0.7%
0.6%
0.5%
0.2%
November
0.1%
0.1%
0%
0%
December
0%
0%
0.1%
0.1%
Neighboring states
Wisconsin: arrives late April, 1 week later than Illinois
Michigan: arrives early May, 2 weeks later than Illinois
Iowa: arrives late April, 1 week later than Illinois
Minnesota: arrives late April, 1 week later than Illinois
Common questions
When do Clay-colored Sparrows arrive in Illinois?
Clay-colored Sparrows mostly pass through Illinois: they arrive in mid April, peak in the second week of May (1.5% of checklists), and most are gone by the second week of July.
When do Clay-colored Sparrows leave Illinois?
Most Clay-colored Sparrows have left Illinois by the second week of July, when reports fall below half their usual rate.
When is the best time to see a Clay-colored Sparrow in Illinois?
The Clay-colored Sparrow is reported most often in the second week of May, on about 1.5% of Illinois checklists.
Where in Illinois are Clay-colored Sparrows seen most often?
By county, Ogle County, Lee County, and Bureau County have the highest peak reporting rates for the Clay-colored Sparrow (counties with at least 200 checklists).