Common Loons are in New Hampshire all year, but most are here in winter: numbers build from mid October, peak in the second week of November (10% of checklists), and fall back by mid January. In the quietest week (mid March) they are still on about 3.6% of checklists.
When to look
Numbers buildOct 15-21mid October
PeakNov 8-14the second week of November
Fall back byJan 15-21mid January
FewestMar 15-21mid March
Best: the second week of November. Here all year; numbers build from mid October and fall back by mid January. Peak: on about 10% of New Hampshire checklists.
Janpeak season
Febcommon
Marcommon
Aprcommon
Maycommon
Junpeak season
Julpeak season
Augpeak season
Sepcommon
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.
Busy spots report more of everything; compare the checklist counts before you drive anywhere.
Best time of day
In New Hampshire, the Common Loon is most often listed on checklists started between 6 and 8 am (7.6% 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
9.1%
7.1%
7.1%
7.0%
February
5.5%
5.9%
5.3%
5.0%
March
5.3%
4.3%
3.2%
3.5%
April
4.7%
5.6%
6.6%
6.7%
May
7.6%
6.8%
6.5%
7.2%
June
7.1%
7.1%
7.2%
8.1%
July
8.6%
8.3%
8.1%
8.7%
August
8.5%
8.8%
8.3%
7.2%
September
7.2%
6.1%
5.7%
6.4%
October
6.7%
7.2%
6.6%
9.4%
November
11%
10%
9.2%
9.4%
December
7.8%
9.0%
6.1%
8.2%
Neighboring states
Massachusetts: arrives late September, 3 weeks earlier than New Hampshire
Vermont: arrives early April, 22 weeks later than New Hampshire
Rhode Island: arrives the second week of October, 1 week earlier than New Hampshire
Common Loons are in New Hampshire all year, but most are here in winter: numbers build from mid October, peak in the second week of November (10% of checklists), and fall back by mid January. In the quietest week (mid March) they are still on about 3.6% of checklists.
When do Common Loons leave New Hampshire?
Common Loons never fully leave New Hampshire: numbers fall back below half their usual rate by mid January, but some are still reported in every week, about 3.6% of checklists at the low.
When is the best time to see a Common Loon in New Hampshire?
The Common Loon is reported most often in the second week of November, on about 10% of New Hampshire checklists.
Where in New Hampshire are Common Loons seen most often?
By county, Belknap County, Rockingham County, and Sullivan County have the highest peak reporting rates for the Common Loon (counties with at least 200 checklists).