Barn Swallows reach New Jersey in early April, are common by late April, peak in early August (37% of checklists), and most are gone by early September.
When to look
First arrivalsApr 1-7early April
Common byApr 22-30late April
PeakAug 1-7early August
Most gone bySep 1-7early September
Best: early August. First arrivals early April; most are gone by early September. Peak: on about 37% of New Jersey checklists.
Jannot usually seen
Febnot usually seen
Marnot usually seen
Aprcommon
Maypeak season
Junpeak season
Julpeak season
Augpeak season
Sepcommon
Octnot usually seen
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 New Jersey 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.
Memorial ParkEssex County, best mid June · 31 checklists that week, 1,662 in all94%
Mercer County ParkMercer County, best the second week of July · 22 checklists that week, 1,500 in all94%
Richard W de Korte ParkBergen County, best the second week of July · 172 checklists that week, 10,095 in all94%
Carnegie LakeMercer County, best late July · 25 checklists that week, 1,444 in all93%
Busy spots report more of everything; compare the checklist counts before you drive anywhere.
Best time of day
In New Jersey, the Barn Swallow is most often listed on checklists started between 5 and 7 pm (17% 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
0.1%
0%
0%
0%
February
0%
0%
0%
0%
March
0.1%
0.1%
0.1%
0.8%
April
3.5%
7.3%
14%
21%
May
27%
29%
32%
32%
June
30%
31%
30%
31%
July
32%
34%
35%
37%
August
38%
37%
36%
26%
September
14%
8.0%
2.2%
1.9%
October
1.3%
1.0%
0.7%
0.8%
November
0.4%
0.6%
0.3%
0.2%
December
0.1%
0.1%
0.1%
0%
Neighboring states
Delaware: arrives the second week of April, 1 week later than New Jersey
Connecticut: arrives the second week of April, 1 week later than New Jersey
Pennsylvania: arrives early April, in the same week than New Jersey
New York: arrives the second week of April, 1 week later than New Jersey
Common questions
When do Barn Swallows arrive in New Jersey?
Barn Swallows reach New Jersey in early April, are common by late April, peak in early August (37% of checklists), and most are gone by early September.
When do Barn Swallows leave New Jersey?
Most Barn Swallows have left New Jersey 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 New Jersey?
The Barn Swallow is reported most often in early August, on about 37% of New Jersey checklists.
Where in New Jersey are Barn Swallows seen most often?
By county, Hudson County, Bergen County, and Cumberland County have the highest peak reporting rates for the Barn Swallow (counties with at least 200 checklists).