WhenToBird

Geothlypis philadelphia · Parulidae

When Do Mourning Warblers Arrive in New Hampshire?

Adult Mourning Warbler
Photo: John Rosford, CC BY 4.0 via iNaturalist

Mourning Warblers mostly pass through New Hampshire: they arrive in mid May, peak in early June (1.5% of checklists), and most are gone by early July.

When to look

First arrivalsMay 15-21mid May
Common byMay 15-21mid May
PeakJun 1-7early June
Most gone byJul 1-7early July

Best: early June. First arrivals mid May; most are gone by early July. Peak: on about 1.5% of New Hampshire checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marnot usually seen
  4. Aprnot usually seen
  5. Maypeak season
  6. Junpeak season
  7. Julcommon
  8. Augrare
  9. Sepuncommon
  10. Octrare
  11. Novnot usually seen
  12. Decnot usually seen

Darker months: more checklists report it. Outlined: peak month.

0%0.5%1%1.5%2%Jan 1-7: 0% of 8253 checklistsJan 8-14: 0% of 5998 checklistsJan 15-21: 0% of 5734 checklistsJan 22-31: 0% of 7776 checklistsFeb 1-7: 0% of 5253 checklistsFeb 8-14: 0% of 6802 checklistsFeb 15-21: 0% of 8852 checklistsFeb 22-28: 0% of 5792 checklistsMar 1-7: 0% of 6187 checklistsMar 8-14: 0% of 6977 checklistsMar 15-21: 0% of 7863 checklistsMar 22-31: 0% of 11746 checklistsApr 1-7: 0% of 9329 checklistsApr 8-14: 0% of 10499 checklistsApr 15-21: 0% of 10376 checklistsApr 22-30: 0% of 13086 checklistsMay 1-7: 0.1% of 13198 checklistsMay 8-14: 0.1% of 14980 checklistsMay 15-21: 0.7% of 12487 checklistsMay 22-31: 1.4% of 14294 checklistsJun 1-7: 1.8% of 8974 checklistsJun 8-14: 1.5% of 8395 checklistsJun 15-21: 1.2% of 7670 checklistsJun 22-30: 0.9% of 9188 checklistsJul 1-7: 0.6% of 7707 checklistsJul 8-14: 0.4% of 6554 checklistsJul 15-21: 0.2% of 6636 checklistsJul 22-31: 0.1% of 9599 checklistsAug 1-7: 0.1% of 6436 checklistsAug 8-14: 0.2% of 6477 checklistsAug 15-21: 0.2% of 6510 checklistsAug 22-31: 0.2% of 9762 checklistsSep 1-7: 0.2% of 6700 checklistsSep 8-14: 0.2% of 6012 checklistsSep 15-21: 0.4% of 6238 checklistsSep 22-30: 0.2% of 7619 checklistsOct 1-7: 0.1% of 6702 checklistsOct 8-14: 0% of 6863 checklistsOct 15-21: 0% of 6284 checklistsOct 22-31: 0.1% of 8287 checklistsNov 1-7: 0% of 7584 checklistsNov 8-14: 0% of 6056 checklistsNov 15-21: 0% of 5597 checklistsNov 22-30: 0% of 7140 checklistsDec 1-7: 0% of 4623 checklistsDec 8-14: 0% of 4920 checklistsDec 15-21: 0% of 6416 checklistsDec 22-31: 0% of 7659 checklistsJanFebMarAprMayJunJulAugSepOctNovDec
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
Second week of November

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.

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Where in New Hampshire

Best counties

Share of checklists at the peak
  1. Coos CountyBest the second week of June · 1296 checklists that week, 27,719 in all8.0%
  2. Grafton CountyBest early June · 1304 checklists that week, 45,699 in all1.4%
  3. Carroll CountyBest early June · 738 checklists that week, 30,580 in all1.3%
  4. Strafford CountyBest late May · 1542 checklists that week, 41,888 in all0.8%
  5. Belknap CountyBest late May · 424 checklists that week, 13,295 in all0.8%
  6. Sullivan CountyBest mid June · 243 checklists that week, 13,105 in all0.8%

Best spots

Share of checklists at the peak
  1. Silvio O. Conte National Fish and Wildlife RefugeCoos County, best mid June · 41 checklists that week, 786 in all38%
  2. Little Cherry PondCoos County, best late May · 27 checklists that week, 287 in all25%
  3. Cherry PondCoos County, best late May · 24 checklists that week, 414 in all14%

Busy spots report more of everything; compare the checklist counts before you drive anywhere.

Best time of day

In New Hampshire, the Mourning Warbler is most often listed on checklists started between 6 and 8 am (0.4% of those checklists).

0%0.5%1%12 am: too few checklists (219) to judge1 am: too few checklists (192) to judge2 am: too few checklists (176) to judge3 am: too few checklists (234) to judge4 am: too few checklists (1042) to judge5 am: too few checklists (6352) to judge6 am: 0.6% of 23140 checklists7 am: 0.4% of 43401 checklists8 am: 0.4% of 48039 checklists9 am: 0.3% of 43328 checklists10 am: 0.3% of 37073 checklists11 am: 0.2% of 32028 checklists12 pm: 0.1% of 27396 checklists1 pm: 0.1% of 25182 checklists2 pm: 0.1% of 24318 checklists3 pm: 0.1% of 21974 checklists4 pm: 0.1% of 17958 checklists5 pm: 0.1% of 14528 checklists6 pm: 0.1% of 9144 checklists7 pm: too few checklists (5341) to judge8 pm: too few checklists (1845) to judge9 pm: too few checklists (578) to judge10 pm: too few checklists (346) to judge11 pm: too few checklists (256) to judge12a3a6a9a12p3p6p9p
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
MonthDays 1-78-1415-2122-end
January0%0%0%0%
February0%0%0%0%
March0%0%0%0%
April0%0%0%0%
May0.1%0.1%0.7%1.4%
June1.8%1.5%1.2%0.9%
July0.6%0.4%0.2%0.1%
August0.1%0.2%0.2%0.2%
September0.2%0.2%0.4%0.2%
October0.1%0%0%0.1%
November0%0%0%0%
December0%0%0%0%

Neighboring states

  • Massachusetts: arrives mid May, in the same week than New Hampshire
  • Vermont: arrives mid May, in the same week than New Hampshire
  • New York: arrives the second week of May, 1 week earlier than New Hampshire
  • District of Columbia: arrives the second week of September, 15 weeks later than New Hampshire

Common questions

When do Mourning Warblers arrive in New Hampshire?
Mourning Warblers mostly pass through New Hampshire: they arrive in mid May, peak in early June (1.5% of checklists), and most are gone by early July.
When do Mourning Warblers leave New Hampshire?
Most Mourning Warblers have left New Hampshire by early July, when reports fall below half their usual rate.
When is the best time to see a Mourning Warbler in New Hampshire?
The Mourning Warbler is reported most often in early June, on about 1.5% of New Hampshire checklists.
Where in New Hampshire are Mourning Warblers seen most often?
By county, Coos County, Grafton County, and Carroll County have the highest peak reporting rates for the Mourning Warbler (counties with at least 200 checklists).