WhenToBird

Cistothorus palustris · Troglodytidae

When Do Marsh Wrens Arrive in Washington?

Adult Marsh Wren
Photo: Kathy Richardson, CC BY 4.0 via iNaturalist

Marsh Wrens are in Washington all year, but most are here in spring: numbers build from mid March, peak in late April (11% of checklists), and fall back by early July. In the quietest week (the second week of August) they are still on about 4.0% of checklists.

When to look

Numbers buildMar 15-21mid March
PeakApr 22-30late April
Fall back byJul 1-7early July
FewestAug 8-14the second week of August

Best: late April. Here all year; numbers build from mid March and fall back by early July. Peak: on about 11% of Washington checklists.

  1. Jancommon
  2. Febcommon
  3. Marpeak season
  4. Aprpeak season
  5. Maypeak season
  6. Junpeak season
  7. Julcommon
  8. Auguncommon
  9. Sepcommon
  10. Octcommon
  11. Novcommon
  12. Deccommon

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

0%5%10%15%Jan 1-7: 4.1% of 41928 checklistsJan 8-14: 4.4% of 31152 checklistsJan 15-21: 4.6% of 31753 checklistsJan 22-31: 4.5% of 42530 checklistsFeb 1-7: 4.0% of 29739 checklistsFeb 8-14: 4.2% of 32746 checklistsFeb 15-21: 3.9% of 40328 checklistsFeb 22-28: 5.8% of 28432 checklistsMar 1-7: 6.4% of 30758 checklistsMar 8-14: 7.3% of 29368 checklistsMar 15-21: 8.6% of 32580 checklistsMar 22-31: 9.4% of 45614 checklistsApr 1-7: 9.5% of 33997 checklistsApr 8-14: 10% of 34729 checklistsApr 15-21: 11% of 38474 checklistsApr 22-30: 11% of 52185 checklistsMay 1-7: 11% of 44236 checklistsMay 8-14: 10% of 48708 checklistsMay 15-21: 9.8% of 41742 checklistsMay 22-31: 9.8% of 57082 checklistsJun 1-7: 9.0% of 39193 checklistsJun 8-14: 8.4% of 36042 checklistsJun 15-21: 8.2% of 34003 checklistsJun 22-30: 8.1% of 39711 checklistsJul 1-7: 7.5% of 31949 checklistsJul 8-14: 7.2% of 29086 checklistsJul 15-21: 5.8% of 28045 checklistsJul 22-31: 4.6% of 38275 checklistsAug 1-7: 4.0% of 28846 checklistsAug 8-14: 3.9% of 28036 checklistsAug 15-21: 4.1% of 27614 checklistsAug 22-31: 4.3% of 40356 checklistsSep 1-7: 4.4% of 31214 checklistsSep 8-14: 4.4% of 27795 checklistsSep 15-21: 4.9% of 29677 checklistsSep 22-30: 5.8% of 35241 checklistsOct 1-7: 6.5% of 28605 checklistsOct 8-14: 6.3% of 28655 checklistsOct 15-21: 6.8% of 24643 checklistsOct 22-31: 6.9% of 34874 checklistsNov 1-7: 6.1% of 25658 checklistsNov 8-14: 6.3% of 25700 checklistsNov 15-21: 6.4% of 24331 checklistsNov 22-30: 6.0% of 32784 checklistsDec 1-7: 5.5% of 24099 checklistsDec 8-14: 5.3% of 23339 checklistsDec 15-21: 4.3% of 27666 checklistsDec 22-31: 4.8% of 42130 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 Washington 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.

Embed this map on your site

Where in Washington

Best counties

Share of checklists at the peak
  1. Adams CountyBest mid May · 201 checklists that week, 4,574 in all28%
  2. Grays Harbor CountyBest late April · 1596 checklists that week, 28,443 in all26%
  3. Clark CountyBest late May · 1937 checklists that week, 53,250 in all21%
  4. Wahkiakum CountyBest late April · 310 checklists that week, 5,618 in all20%
  5. Garfield CountyBest the second week of November · 36 checklists that week, 1,130 in all20%
  6. Skagit CountyBest mid May · 1702 checklists that week, 78,154 in all18%

Best spots

Share of checklists at the peak
  1. Gloyd SeepsGrant County, best mid May · 27 checklists that week, 395 in all99%
  2. Canal RoadCowlitz County, best the second week of May · 22 checklists that week, 700 in all98%
  3. Sportsmans LakeSan Juan County, best mid May · 25 checklists that week, 609 in all98%
  4. Billy Frank Jr. Nisqually National Wildlife Refuge (Jansen Hill)Pierce County, best the second week of March · 21 checklists that week, 232 in all97%

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

Best time of day

In Washington, the Marsh Wren is most often listed on checklists started between 6 and 8 am (8.9% of those checklists).

0%5%10%12 am: too few checklists (796) to judge1 am: too few checklists (776) to judge2 am: too few checklists (709) to judge3 am: too few checklists (901) to judge4 am: too few checklists (3221) to judge5 am: too few checklists (16576) to judge6 am: 9.7% of 56744 checklists7 am: 8.6% of 133294 checklists8 am: 8.2% of 184196 checklists9 am: 7.5% of 186303 checklists10 am: 7.1% of 177063 checklists11 am: 6.4% of 154936 checklists12 pm: 5.9% of 138061 checklists1 pm: 5.9% of 127449 checklists2 pm: 5.8% of 121511 checklists3 pm: 5.6% of 107793 checklists4 pm: 5.6% of 82862 checklists5 pm: 6.0% of 57183 checklists6 pm: 6.1% of 39886 checklists7 pm: too few checklists (26969) to judge8 pm: too few checklists (12427) to judge9 pm: too few checklists (3658) to judge10 pm: too few checklists (1500) to judge11 pm: too few checklists (834) 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
January4.1%4.4%4.6%4.5%
February4.0%4.2%3.9%5.8%
March6.4%7.3%8.6%9.4%
April9.5%10%11%11%
May11%10%9.8%9.8%
June9.0%8.4%8.2%8.1%
July7.5%7.2%5.8%4.6%
August4.0%3.9%4.1%4.3%
September4.4%4.4%4.9%5.8%
October6.5%6.3%6.8%6.9%
November6.1%6.3%6.4%6.0%
December5.5%5.3%4.3%4.8%

Neighboring states

  • Oregon: year-round, peaks the second week of April
  • Idaho: arrives late February, 3 weeks earlier than Washington
  • Montana: arrives early April, 2 weeks later than Washington
  • Nevada: arrives mid September, 24 weeks earlier than Washington

Common questions

When do Marsh Wrens arrive in Washington?
Marsh Wrens are in Washington all year, but most are here in spring: numbers build from mid March, peak in late April (11% of checklists), and fall back by early July. In the quietest week (the second week of August) they are still on about 4.0% of checklists.
When do Marsh Wrens leave Washington?
Marsh Wrens never fully leave Washington: numbers fall back below half their usual rate by early July, but some are still reported in every week, about 4.0% of checklists at the low.
When is the best time to see a Marsh Wren in Washington?
The Marsh Wren is reported most often in late April, on about 11% of Washington checklists.
Where in Washington are Marsh Wrens seen most often?
By county, Adams County, Grays Harbor County, and Clark County have the highest peak reporting rates for the Marsh Wren (counties with at least 200 checklists).