WhenToBird

Hydroprogne caspia · Laridae

When Do Caspian Terns Arrive in Minnesota?

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

Caspian Terns arrive in Minnesota in late April, peak in the second week of May (2.3% of checklists), and most are gone by the second week of June.

When to look

First arrivalsApr 22-30late April
Common byApr 22-30late April
PeakMay 8-14the second week of May
Most gone byJun 8-14the second week of June

Best: the second week of May. First arrivals late April; most are gone by the second week of June. Peak: on about 2.3% of Minnesota checklists.

  1. Jannot usually seen
  2. Febnot usually seen
  3. Marnot usually seen
  4. Apruncommon
  5. Maypeak season
  6. Juncommon
  7. Juluncommon
  8. Augcommon
  9. Sepcommon
  10. Octuncommon
  11. Novnot usually seen
  12. Decnot usually seen

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

0%1%2%3%4%Jan 1-7: 0% of 20628 checklistsJan 8-14: 0% of 14594 checklistsJan 15-21: 0% of 14238 checklistsJan 22-31: 0% of 20725 checklistsFeb 1-7: 0% of 14484 checklistsFeb 8-14: 0% of 15988 checklistsFeb 15-21: 0% of 20718 checklistsFeb 22-28: 0% of 15754 checklistsMar 1-7: 0% of 16125 checklistsMar 8-14: 0% of 19035 checklistsMar 15-21: 0% of 19586 checklistsMar 22-31: 0% of 30192 checklistsApr 1-7: 0% of 24262 checklistsApr 8-14: 0.1% of 30223 checklistsApr 15-21: 0.1% of 29085 checklistsApr 22-30: 0.6% of 43574 checklistsMay 1-7: 1.7% of 39300 checklistsMay 8-14: 2.3% of 45927 checklistsMay 15-21: 3.0% of 36632 checklistsMay 22-31: 1.7% of 43809 checklistsJun 1-7: 0.8% of 23418 checklistsJun 8-14: 0.5% of 20450 checklistsJun 15-21: 0.4% of 19470 checklistsJun 22-30: 0.4% of 23418 checklistsJul 1-7: 0.4% of 19104 checklistsJul 8-14: 0.3% of 16927 checklistsJul 15-21: 0.5% of 15635 checklistsJul 22-31: 0.6% of 22073 checklistsAug 1-7: 0.8% of 16255 checklistsAug 8-14: 0.9% of 16840 checklistsAug 15-21: 1.2% of 17475 checklistsAug 22-31: 1.3% of 26545 checklistsSep 1-7: 1.5% of 20750 checklistsSep 8-14: 0.7% of 18494 checklistsSep 15-21: 0.7% of 18215 checklistsSep 22-30: 0.3% of 24463 checklistsOct 1-7: 0.4% of 18252 checklistsOct 8-14: 0.6% of 19527 checklistsOct 15-21: 0.1% of 17098 checklistsOct 22-31: 0.1% of 24570 checklistsNov 1-7: 0% of 16744 checklistsNov 8-14: 0% of 13483 checklistsNov 15-21: 0% of 12525 checklistsNov 22-30: 0% of 17023 checklistsDec 1-7: 0% of 11645 checklistsDec 8-14: 0% of 11567 checklistsDec 15-21: 0% of 13343 checklistsDec 22-31: 0% of 19759 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 Minnesota 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 Minnesota

Best counties

Share of checklists at the peak
  1. Hubbard CountyBest the second week of August · 103 checklists that week, 5,131 in all24%
  2. Cass CountyBest the second week of August · 245 checklists that week, 10,555 in all16%
  3. Faribault CountyBest early September · 41 checklists that week, 1,448 in all10%
  4. Wadena CountyBest late May · 46 checklists that week, 681 in all8.8%
  5. Chippewa CountyBest early September · 34 checklists that week, 1,298 in all7.5%
  6. Carver CountyBest mid May · 858 checklists that week, 20,549 in all6.5%

Best spots

Share of checklists at the peak
  1. Spring Lake (Sedil)Dakota County, best mid September · 45 checklists that week, 256 in all84%
  2. Rice LakeHennepin County, best the second week of May · 44 checklists that week, 438 in all83%
  3. Kabekona LakeHubbard County, best early June · 29 checklists that week, 1,402 in all72%
  4. Central Park (west)Hennepin County, best the second week of May · 33 checklists that week, 872 in all60%

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

Best time of day

In Minnesota, the Caspian Tern is most often listed on checklists started between 6 and 8 pm (0.9% of those checklists).

0%0.5%1%1.5%12 am: too few checklists (349) to judge1 am: too few checklists (331) to judge2 am: too few checklists (286) to judge3 am: too few checklists (364) to judge4 am: too few checklists (863) to judge5 am: too few checklists (7598) to judge6 am: 1.3% of 35775 checklists7 am: 0.7% of 90565 checklists8 am: 0.5% of 110612 checklists9 am: 0.5% of 106128 checklists10 am: 0.5% of 96131 checklists11 am: 0.5% of 83750 checklists12 pm: 0.5% of 76254 checklists1 pm: 0.6% of 73480 checklists2 pm: 0.5% of 73703 checklists3 pm: 0.5% of 75249 checklists4 pm: 0.6% of 68810 checklists5 pm: 0.8% of 51899 checklists6 pm: 1.0% of 38524 checklists7 pm: 0.8% of 25120 checklists8 pm: too few checklists (10568) to judge9 pm: too few checklists (2420) to judge10 pm: too few checklists (748) to judge11 pm: too few checklists (420) 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%0.1%0.1%0.6%
May1.7%2.3%3.0%1.7%
June0.8%0.5%0.4%0.4%
July0.4%0.3%0.5%0.6%
August0.8%0.9%1.2%1.3%
September1.5%0.7%0.7%0.3%
October0.4%0.6%0.1%0.1%
November0%0%0%0%
December0%0%0%0%

Neighboring states

  • Iowa: arrives late July, 12 weeks later than Minnesota
  • Wisconsin: arrives the second week of April, 2 weeks earlier than Minnesota
  • South Dakota: arrives mid April, 1 week earlier than Minnesota
  • North Dakota: arrives late April, in the same week than Minnesota

Common questions

When do Caspian Terns arrive in Minnesota?
Caspian Terns arrive in Minnesota in late April, peak in the second week of May (2.3% of checklists), and most are gone by the second week of June.
When do Caspian Terns leave Minnesota?
Most Caspian Terns have left Minnesota by the second week of June, when reports fall below half their usual rate.
When is the best time to see a Caspian Tern in Minnesota?
The Caspian Tern is reported most often in the second week of May, on about 2.3% of Minnesota checklists.
Where in Minnesota are Caspian Terns seen most often?
By county, Hubbard County, Cass County, and Faribault County have the highest peak reporting rates for the Caspian Tern (counties with at least 200 checklists).