WhenToBird

Calidris pusilla · Scolopacidae

When Do Semipalmated Sandpipers Arrive in Washington?

Adult Semipalmated Sandpiper
Photo: Kathy Richardson, CC BY 4.0 via iNaturalist

Semipalmated Sandpipers mostly pass through Washington: they arrive in early July, peak in mid August (1.7% of checklists), and most are gone by early September.

When to look

First arrivalsJul 1-7early July
Common byJul 1-7early July
PeakAug 15-21mid August
Most gone bySep 1-7early September

Best: mid August. First arrivals early July; most are gone by early September. Peak: on about 1.7% of Washington checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marnot usually seen
  4. Aprnot usually seen
  5. Mayrare
  6. Jununcommon
  7. Julcommon
  8. Augpeak season
  9. Sepcommon
  10. Octnot usually seen
  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 41928 checklistsJan 8-14: 0% of 31152 checklistsJan 15-21: 0% of 31753 checklistsJan 22-31: 0% of 42530 checklistsFeb 1-7: 0% of 29739 checklistsFeb 8-14: 0% of 32746 checklistsFeb 15-21: 0% of 40328 checklistsFeb 22-28: 0% of 28432 checklistsMar 1-7: 0% of 30758 checklistsMar 8-14: 0% of 29368 checklistsMar 15-21: 0% of 32580 checklistsMar 22-31: 0% of 45614 checklistsApr 1-7: 0% of 33997 checklistsApr 8-14: 0% of 34729 checklistsApr 15-21: 0.1% of 38474 checklistsApr 22-30: 0.1% of 52185 checklistsMay 1-7: 0.1% of 44236 checklistsMay 8-14: 0.1% of 48708 checklistsMay 15-21: 0.1% of 41742 checklistsMay 22-31: 0.1% of 57082 checklistsJun 1-7: 0.1% of 39193 checklistsJun 8-14: 0.1% of 36042 checklistsJun 15-21: 0% of 34003 checklistsJun 22-30: 0.2% of 39711 checklistsJul 1-7: 0.7% of 31949 checklistsJul 8-14: 1.1% of 29086 checklistsJul 15-21: 1.0% of 28045 checklistsJul 22-31: 1.2% of 38275 checklistsAug 1-7: 1.5% of 28846 checklistsAug 8-14: 1.7% of 28036 checklistsAug 15-21: 1.7% of 27614 checklistsAug 22-31: 1.7% of 40356 checklistsSep 1-7: 1.1% of 31214 checklistsSep 8-14: 0.5% of 27795 checklistsSep 15-21: 0.2% of 29677 checklistsSep 22-30: 0.1% of 35241 checklistsOct 1-7: 0.1% of 28605 checklistsOct 8-14: 0.1% of 28655 checklistsOct 15-21: 0% of 24643 checklistsOct 22-31: 0% of 34874 checklistsNov 1-7: 0% of 25658 checklistsNov 8-14: 0% of 25700 checklistsNov 15-21: 0% of 24331 checklistsNov 22-30: 0% of 32784 checklistsDec 1-7: 0% of 24099 checklistsDec 8-14: 0% of 23339 checklistsDec 15-21: 0% of 27666 checklistsDec 22-31: 0% 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.

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Where in Washington

Best counties

Share of checklists at the peak
  1. Adams CountyBest mid August · 103 checklists that week, 4,574 in all15%
  2. Grant CountyBest mid August · 278 checklists that week, 19,963 in all15%
  3. Asotin CountyBest the second week of August · 60 checklists that week, 4,316 in all11%
  4. Skagit CountyBest the second week of August · 1273 checklists that week, 78,154 in all4.5%
  5. Grays Harbor CountyBest late July · 990 checklists that week, 28,443 in all4.5%
  6. Franklin CountyBest mid August · 113 checklists that week, 7,970 in all4.4%

Best spots

Share of checklists at the peak
  1. Fort CaseyIsland County, best early July · 29 checklists that week, 1,530 in all38%
  2. Old ChannelSkagit County, best mid July · 33 checklists that week, 1,445 in all36%
  3. Jetty Island Nature PreserveSnohomish County, best the second week of July · 25 checklists that week, 356 in all32%

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

Best time of day

In Washington, the Semipalmated Sandpiper is most often listed on checklists started between 5 and 7 pm (0.4% of those checklists).

0%0.5%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: 0.4% of 56744 checklists7 am: 0.3% of 133294 checklists8 am: 0.2% of 184196 checklists9 am: 0.2% of 186303 checklists10 am: 0.2% of 177063 checklists11 am: 0.2% of 154936 checklists12 pm: 0.2% of 138061 checklists1 pm: 0.2% of 127449 checklists2 pm: 0.2% of 121511 checklists3 pm: 0.2% of 107793 checklists4 pm: 0.2% of 82862 checklists5 pm: 0.4% of 57183 checklists6 pm: 0.4% 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
January0%0%0%0%
February0%0%0%0%
March0%0%0%0%
April0%0%0.1%0.1%
May0.1%0.1%0.1%0.1%
June0.1%0.1%0%0.2%
July0.7%1.1%1.0%1.2%
August1.5%1.7%1.7%1.7%
September1.1%0.5%0.2%0.1%
October0.1%0.1%0%0%
November0%0%0%0%
December0%0%0%0%

Neighboring states

  • Oregon: arrives mid July, 2 weeks later than Washington
  • Idaho: arrives mid July, 2 weeks later than Washington
  • Montana: arrives mid July, 2 weeks later than Washington
  • Nevada: arrives late July, 3 weeks later than Washington

Common questions

When do Semipalmated Sandpipers arrive in Washington?
Semipalmated Sandpipers mostly pass through Washington: they arrive in early July, peak in mid August (1.7% of checklists), and most are gone by early September.
When do Semipalmated Sandpipers leave Washington?
Most Semipalmated Sandpipers have left Washington by early September, when reports fall below half their usual rate.
When is the best time to see a Semipalmated Sandpiper in Washington?
The Semipalmated Sandpiper is reported most often in mid August, on about 1.7% of Washington checklists.
Where in Washington are Semipalmated Sandpipers seen most often?
By county, Adams County, Grant County, and Asotin County have the highest peak reporting rates for the Semipalmated Sandpiper (counties with at least 200 checklists).