American Herring Gulls are in New Hampshire all year, but most are here in fall: numbers build from the second week of August, peak in early January (17% of checklists), and fall back by early February. In the quietest week (late June) they are still on about 6.3% of checklists.
When to look
Numbers buildAug 8-14the second week of August
PeakJan 1-7early January
Fall back byFeb 1-7early February
FewestJun 22-30late June
Best: early January. Here all year; numbers build from the second week of August and fall back by early February. Peak: on about 17% of New Hampshire checklists.
Janpeak season
Febpeak season
Marpeak season
Aprcommon
Maycommon
Juncommon
Julcommon
Augpeak season
Seppeak season
Octpeak season
Novpeak season
Decpeak season
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 Hampshire 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.
Cocheco River ReservoirStrafford County, best early January · 46 checklists that week, 2,281 in all95%
Pickering Ponds Recreation AreaStrafford County, best the second week of November · 60 checklists that week, 5,064 in all95%
Busy spots report more of everything; compare the checklist counts before you drive anywhere.
Best time of day
In New Hampshire, the American Herring Gull is most often listed on checklists started between 10 am and 12 pm (13% 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
When do American Herring Gulls arrive in New Hampshire?
American Herring Gulls are in New Hampshire all year, but most are here in fall: numbers build from the second week of August, peak in early January (17% of checklists), and fall back by early February. In the quietest week (late June) they are still on about 6.3% of checklists.
When do American Herring Gulls leave New Hampshire?
American Herring Gulls never fully leave New Hampshire: numbers fall back below half their usual rate by early February, but some are still reported in every week, about 6.3% of checklists at the low.
When is the best time to see a American Herring Gull in New Hampshire?
The American Herring Gull is reported most often in early January, on about 17% of New Hampshire checklists.
Where in New Hampshire are American Herring Gulls seen most often?
By county, Rockingham County, Strafford County, and Hillsborough County have the highest peak reporting rates for the American Herring Gull (counties with at least 200 checklists).