WhenToBird

Cardellina canadensis · Parulidae

When Do Canada Warblers Arrive in Maryland?

Adult male Canada Warbler
Photo: Hugo Bernal Hernández, CC BY 4.0 via iNaturalist

Canada Warblers mostly pass through Maryland: they arrive in the second week of August, peak in early September (3.6% of checklists), and most are gone by late September.

When to look

First arrivalsAug 8-14the second week of August
Common byAug 8-14the second week of August
PeakSep 1-7early September
Most gone bySep 22-30late September

Best: early September. First arrivals the second week of August; most are gone by late September. Peak: on about 3.6% of Maryland checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marnot usually seen
  4. Aprrare
  5. Maypeak season
  6. Jununcommon
  7. Julrare
  8. Augpeak season
  9. Seppeak season
  10. Octrare
  11. Novnot usually seen
  12. Decnot usually seen

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

0%2%4%6%Jan 1-7: 0% of 28716 checklistsJan 8-14: 0% of 21449 checklistsJan 15-21: 0% of 21267 checklistsJan 22-31: 0% of 29144 checklistsFeb 1-7: 0% of 21347 checklistsFeb 8-14: 0% of 22166 checklistsFeb 15-21: 0% of 29986 checklistsFeb 22-28: 0% of 22427 checklistsMar 1-7: 0% of 21389 checklistsMar 8-14: 0% of 22192 checklistsMar 15-21: 0% of 22823 checklistsMar 22-31: 0% of 33720 checklistsApr 1-7: 0% of 25513 checklistsApr 8-14: 0% of 27718 checklistsApr 15-21: 0% of 29328 checklistsApr 22-30: 0.1% of 42595 checklistsMay 1-7: 1.2% of 38532 checklistsMay 8-14: 3.6% of 42722 checklistsMay 15-21: 5.3% of 31936 checklistsMay 22-31: 1.9% of 36903 checklistsJun 1-7: 0.4% of 23191 checklistsJun 8-14: 0.3% of 21853 checklistsJun 15-21: 0.5% of 21000 checklistsJun 22-30: 0.2% of 25133 checklistsJul 1-7: 0.2% of 18715 checklistsJul 8-14: 0.1% of 16376 checklistsJul 15-21: 0.1% of 15793 checklistsJul 22-31: 0.1% of 21969 checklistsAug 1-7: 0.2% of 16013 checklistsAug 8-14: 0.4% of 15249 checklistsAug 15-21: 1.5% of 15674 checklistsAug 22-31: 3.9% of 24925 checklistsSep 1-7: 4.1% of 19808 checklistsSep 8-14: 2.6% of 18513 checklistsSep 15-21: 1.2% of 21901 checklistsSep 22-30: 0.4% of 22901 checklistsOct 1-7: 0.1% of 19111 checklistsOct 8-14: 0.1% of 18482 checklistsOct 15-21: 0.1% of 17380 checklistsOct 22-31: 0% of 23992 checklistsNov 1-7: 0% of 17915 checklistsNov 8-14: 0% of 18905 checklistsNov 15-21: 0% of 16259 checklistsNov 22-30: 0% of 22852 checklistsDec 1-7: 0% of 16108 checklistsDec 8-14: 0% of 16512 checklistsDec 15-21: 0% of 18952 checklistsDec 22-31: 0% of 29728 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 Maryland 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 Maryland

Best counties

Share of checklists at the peak
  1. Harford CountyBest early September · 551 checklists that week, 39,311 in all8.4%
  2. Baltimore CountyBest early September · 2528 checklists that week, 136,139 in all7.5%
  3. Garrett CountyBest late May · 1675 checklists that week, 37,616 in all7.3%
  4. Cecil CountyBest early September · 392 checklists that week, 18,620 in all7.3%
  5. Howard CountyBest mid May · 3407 checklists that week, 118,290 in all5.5%
  6. Montgomery CountyBest early September · 4175 checklists that week, 219,548 in all5.4%

Best spots

Share of checklists at the peak
  1. New Germany SpGarrett County, best late May · 60 checklists that week, 779 in all48%
  2. Gorman Stream ValleyHoward County, best mid May · 23 checklists that week, 262 in all46%
  3. Swallow Falls SpGarrett County, best the second week of June · 21 checklists that week, 436 in all42%
  4. Pine Lake (Kemp Mill Farms)Montgomery County, best late August · 38 checklists that week, 771 in all40%
  5. Spring BranchBaltimore County, best late August · 29 checklists that week, 446 in all39%

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

Best time of day

In Maryland, the Canada Warbler is most often listed on checklists started between 6 and 8 am (1.6% of those checklists).

0%1%2%3%12 am: too few checklists (486) to judge1 am: too few checklists (451) to judge2 am: too few checklists (447) to judge3 am: too few checklists (766) to judge4 am: too few checklists (2076) to judge5 am: too few checklists (11098) to judge6 am: 2.1% of 56604 checklists7 am: 1.4% of 139255 checklists8 am: 0.9% of 148626 checklists9 am: 0.7% of 126820 checklists10 am: 0.5% of 106973 checklists11 am: 0.4% of 87483 checklists12 pm: 0.3% of 74808 checklists1 pm: 0.3% of 69428 checklists2 pm: 0.3% of 67800 checklists3 pm: 0.3% of 67688 checklists4 pm: 0.3% of 60927 checklists5 pm: 0.4% of 43876 checklists6 pm: 0.3% of 32930 checklists7 pm: too few checklists (19051) to judge8 pm: too few checklists (5708) to judge9 pm: too few checklists (1977) to judge10 pm: too few checklists (1170) to judge11 pm: too few checklists (635) 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%0.1%
May1.2%3.6%5.3%1.9%
June0.4%0.3%0.5%0.2%
July0.2%0.1%0.1%0.1%
August0.2%0.4%1.5%3.9%
September4.1%2.6%1.2%0.4%
October0.1%0.1%0.1%0%
November0%0%0%0%
December0%0%0%0%

Neighboring states

  • District of Columbia: arrives early May, 13 weeks earlier than Maryland
  • Delaware: arrives mid August, 1 week later than Maryland
  • Virginia: arrives late April, 14 weeks earlier than Maryland
  • Pennsylvania: arrives early May, 13 weeks earlier than Maryland

Common questions

When do Canada Warblers arrive in Maryland?
Canada Warblers mostly pass through Maryland: they arrive in the second week of August, peak in early September (3.6% of checklists), and most are gone by late September.
When do Canada Warblers leave Maryland?
Most Canada Warblers have left Maryland by late September, when reports fall below half their usual rate.
When is the best time to see a Canada Warbler in Maryland?
The Canada Warbler is reported most often in early September, on about 3.6% of Maryland checklists.
Where in Maryland are Canada Warblers seen most often?
By county, Harford County, Baltimore County, and Garrett County have the highest peak reporting rates for the Canada Warbler (counties with at least 200 checklists).