LinerIndex  /  Indices  /  LMI

Maritime Activity Index

How busy commercial ports are, month by month — seasonally adjusted, so the line shows the cycle rather than the calendar. Base 2019 = 100.

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Trend ·
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Year on year
Seasonally adjusted
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Last 3 months
Change in trend
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2020 low

United States · 2018 – 2024

Source: LinerIndex, from NOAA AIS vessel positions in U.S. ports. Monthly averages, seasonally adjusted.

Year-on-year change

% vs same month a year earlier · adjusted series

Europe

Pilot · Jun – Jul 2026 · feed paused

Weekly index, European ports

Based on our own AIS capture. Seven weeks is too short to estimate seasonality, so this series is shown as weekly averages, without adjustment. Base = pilot period average.

What moves the unadjusted line

Seasonal factors estimated on 2018–2024: activity runs about 2% above average in February–April and October, and about 3% below in July and August. The adjusted series removes this pattern.

Methodology

How the index is built

  • Daily activity: distinct commercial vessels in port each day, from AIS positions.
  • Monthly average of the daily index, which removes day-of-week and holiday noise.
  • Seasonal adjustment: classical multiplicative decomposition — a 2×12 centred moving average, and one stable seasonal factor per calendar month.
  • Trend: 5-month Henderson filter on the adjusted series, with asymmetric weights at the end.
  • Base: 2019 average = 100.

Read with care

  • The last two months of the trend are provisional: they are revised as new data arrives.
  • The panel averages about 22 ports a day, and the number observed varies. A fixed panel of ports is planned, to remove that source of noise.
  • The jump between March and April 2021 (+18%) is under review, to separate the real post-lockdown rebound from a change in coverage.