WhenToBird

Hydroprogne caspia · Laridae

When Do Caspian Terns Arrive in South Carolina?

Adult Caspian Tern
Photo: Daughter Dad, CC BY 4.0 via iNaturalist

Caspian Terns reach South Carolina in early July, are common by early August, peak in mid September (4.5% of checklists), and most are gone by the second week of November.

When to look

First arrivalsJul 1-7early July
Common byAug 1-7early August
PeakSep 15-21mid September
Most gone byNov 8-14the second week of November

Best: mid September. First arrivals early July; most are gone by the second week of November. Peak: on about 4.5% of South Carolina checklists.

  1. Janrare
  2. Febrare
  3. Maruncommon
  4. Apruncommon
  5. Mayuncommon
  6. Jununcommon
  7. Juluncommon
  8. Augcommon
  9. Seppeak season
  10. Octpeak season
  11. Novcommon
  12. Decuncommon

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

0%2%4%6%Jan 1-7: 0.5% of 15487 checklistsJan 8-14: 0.5% of 11691 checklistsJan 15-21: 0.3% of 11994 checklistsJan 22-31: 0.3% of 16225 checklistsFeb 1-7: 0.3% of 12192 checklistsFeb 8-14: 0.5% of 14044 checklistsFeb 15-21: 0.3% of 18483 checklistsFeb 22-28: 0.4% of 12045 checklistsMar 1-7: 0.4% of 11511 checklistsMar 8-14: 0.5% of 11704 checklistsMar 15-21: 0.8% of 11526 checklistsMar 22-31: 0.7% of 17386 checklistsApr 1-7: 0.9% of 13148 checklistsApr 8-14: 1.1% of 13193 checklistsApr 15-21: 1.3% of 13936 checklistsApr 22-30: 0.8% of 19002 checklistsMay 1-7: 0.7% of 14133 checklistsMay 8-14: 0.7% of 13668 checklistsMay 15-21: 0.9% of 11064 checklistsMay 22-31: 0.8% of 14461 checklistsJun 1-7: 1.1% of 10231 checklistsJun 8-14: 0.9% of 9417 checklistsJun 15-21: 0.9% of 8012 checklistsJun 22-30: 0.9% of 9720 checklistsJul 1-7: 1.1% of 7907 checklistsJul 8-14: 1.6% of 7338 checklistsJul 15-21: 1.2% of 7312 checklistsJul 22-31: 1.8% of 10877 checklistsAug 1-7: 1.8% of 7816 checklistsAug 8-14: 2.0% of 7655 checklistsAug 15-21: 2.7% of 7797 checklistsAug 22-31: 3.3% of 11246 checklistsSep 1-7: 4.0% of 8956 checklistsSep 8-14: 4.4% of 8929 checklistsSep 15-21: 4.1% of 9389 checklistsSep 22-30: 4.9% of 13028 checklistsOct 1-7: 4.2% of 11063 checklistsOct 8-14: 4.0% of 10968 checklistsOct 15-21: 4.9% of 10264 checklistsOct 22-31: 4.4% of 12917 checklistsNov 1-7: 2.7% of 8802 checklistsNov 8-14: 2.2% of 8339 checklistsNov 15-21: 1.6% of 8798 checklistsNov 22-30: 1.0% of 12925 checklistsDec 1-7: 0.7% of 8541 checklistsDec 8-14: 0.4% of 8609 checklistsDec 15-21: 0.6% of 9961 checklistsDec 22-31: 0.5% of 17541 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 South Carolina 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 South Carolina

Best counties

Share of checklists at the peak
  1. Jasper CountyBest the second week of September · 210 checklists that week, 12,443 in all29%
  2. Georgetown CountyBest the second week of October · 648 checklists that week, 32,234 in all20%
  3. Colleton CountyBest late October · 303 checklists that week, 8,909 in all9.4%
  4. Beaufort CountyBest late September · 1259 checklists that week, 60,298 in all8.8%
  5. Horry CountyBest the second week of October · 598 checklists that week, 27,518 in all8.1%
  6. Clarendon CountyBest mid September · 191 checklists that week, 9,189 in all7.8%

Best spots

Share of checklists at the peak
  1. Huntington Beach State Park (Murrells Inlet)Georgetown County, best late September · 32 checklists that week, 1,488 in all70%
  2. Lighthouse Inlet Heritage PreserveCharleston County, best mid September · 37 checklists that week, 1,859 in all46%

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

Best time of day

In South Carolina, the Caspian Tern is most often listed on checklists started between 6 and 8 am (2.2% of those checklists).

0%1%2%3%12 am: too few checklists (222) to judge1 am: too few checklists (160) to judge2 am: too few checklists (132) to judge3 am: too few checklists (212) to judge4 am: too few checklists (267) to judge5 am: too few checklists (1898) to judge6 am: 1.9% of 19280 checklists7 am: 2.2% of 66492 checklists8 am: 1.5% of 73941 checklists9 am: 1.6% of 63039 checklists10 am: 1.6% of 52652 checklists11 am: 1.3% of 41908 checklists12 pm: 1.2% of 36782 checklists1 pm: 1.5% of 33300 checklists2 pm: 1.4% of 32248 checklists3 pm: 1.2% of 35451 checklists4 pm: 1.2% of 34410 checklists5 pm: 1.2% of 27073 checklists6 pm: 1.0% of 17375 checklists7 pm: too few checklists (10313) to judge8 pm: too few checklists (2756) to judge9 pm: too few checklists (672) to judge10 pm: too few checklists (412) 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
January0.5%0.5%0.3%0.3%
February0.3%0.5%0.3%0.4%
March0.4%0.5%0.8%0.7%
April0.9%1.1%1.3%0.8%
May0.7%0.7%0.9%0.8%
June1.1%0.9%0.9%0.9%
July1.1%1.6%1.2%1.8%
August1.8%2.0%2.7%3.3%
September4.0%4.4%4.1%4.9%
October4.2%4.0%4.9%4.4%
November2.7%2.2%1.6%1.0%
December0.7%0.4%0.6%0.5%

Neighboring states

  • North Carolina: arrives late July, 3 weeks later than South Carolina
  • Georgia: arrives the second week of August, 5 weeks later than South Carolina
  • Tennessee: arrives mid July, 2 weeks later than South Carolina
  • Virginia: arrives the second week of July, 1 week later than South Carolina

Common questions

When do Caspian Terns arrive in South Carolina?
Caspian Terns reach South Carolina in early July, are common by early August, peak in mid September (4.5% of checklists), and most are gone by the second week of November.
When do Caspian Terns leave South Carolina?
Most Caspian Terns have left South Carolina by the second week of November, when reports fall below half their usual rate. Stragglers are still reported until late November.
When is the best time to see a Caspian Tern in South Carolina?
The Caspian Tern is reported most often in mid September, on about 4.5% of South Carolina checklists.
Where in South Carolina are Caspian Terns seen most often?
By county, Jasper County, Georgetown County, and Colleton County have the highest peak reporting rates for the Caspian Tern (counties with at least 200 checklists).