Rose-breasted Grosbeaks reach Connecticut in mid April, are common by late April, peak in the second week of May (22% of checklists), and most are gone by mid September.
When to look
First arrivalsApr 15-21mid April
Common byApr 22-30late April
PeakMay 8-14the second week of May
Most gone bySep 15-21mid September
Best: the second week of May. First arrivals mid April; most are gone by mid September. Peak: on about 22% of Connecticut checklists.
Jannot usually seen
Febnot usually seen
Marnot usually seen
Aprcommon
Maypeak season
Juncommon
Julcommon
Auguncommon
Sepuncommon
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 Connecticut 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.
Lake Mohegan Recreation AreaFairfield County, best the second week of May · 70 checklists that week, 703 in all79%
Dooley PondMiddlesex County, best the second week of May · 22 checklists that week, 344 in all77%
Great SwampNew London County, best the second week of May · 21 checklists that week, 165 in all71%
Busy spots report more of everything; compare the checklist counts before you drive anywhere.
Best time of day
In Connecticut, the Rose-breasted Grosbeak is most often listed on checklists started between 6 and 8 am (9.5% 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
0.1%
0.1%
0.1%
4.5%
May
20%
24%
22%
15%
June
12%
12%
12%
12%
July
10%
8.4%
6.1%
5.1%
August
5.0%
3.8%
3.4%
3.6%
September
3.9%
6.6%
6.5%
4.1%
October
1.6%
0.4%
0.1%
0.1%
November
0.1%
0.1%
0%
0.1%
December
0.1%
0%
0%
0%
Neighboring states
Rhode Island: arrives late April, 1 week later than Connecticut
Massachusetts: arrives late April, 1 week later than Connecticut
New Jersey: arrives mid April, in the same week than Connecticut
New York: arrives mid April, in the same week than Connecticut
Common questions
When do Rose-breasted Grosbeaks arrive in Connecticut?
Rose-breasted Grosbeaks reach Connecticut in mid April, are common by late April, peak in the second week of May (22% of checklists), and most are gone by mid September.
When do Rose-breasted Grosbeaks leave Connecticut?
Most Rose-breasted Grosbeaks have left Connecticut by mid September, when reports fall below half their usual rate. Stragglers are still reported until early October.
When is the best time to see a Rose-breasted Grosbeak in Connecticut?
The Rose-breasted Grosbeak is reported most often in the second week of May, on about 22% of Connecticut checklists.
Where in Connecticut are Rose-breasted Grosbeaks seen most often?
By county, Windham County, Litchfield County, and Tolland County have the highest peak reporting rates for the Rose-breasted Grosbeak (counties with at least 200 checklists).