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Where high tides flood more often than they used to
Each dot is a tide gauge, coloured by how its flood days a year over the last ten years compare with 2005–2014. Click a dot for its numbers.
| Region | Gauges | Flooding more often | At least twice as often | Less often | Still rare |
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Europe, Africa and mainland Asia have few gauges here: many national networks do not share hourly data through the global archive this dashboard uses.
Flood days a year at the gauge you choose
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Which gauges flood most often?
Average flood days a year, most first. The 18 NOAA gauges use NOAA’s official counts; the rest are calculated by us the same way NOAA sets its thresholds. Gauges with very large tides are left out.
| Gauge | Country | 2005–2014 | Last 10 years | Change |
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Show the other — gauges
| Gauge | Country | 2005–2014 | Last 10 years | Change |
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United States: live detail from NOAA
For 18 US gauges NOAA also publishes live readings, tide predictions, official flood counts and local sea level projections.
Water level at the US gauges now
Orange and red gauges are at flood level.
Readings at all 18 US gauges
| Gauge | Now, vs average high tide | Weather effect | Flood level | Status |
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Heights in metres above the average daily high tide (MHHW). Weather effect = measured level minus the predicted tide: wind and air pressure pushing water up (storm surge) or down.
High tides in the next 7 days
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How much higher by 2050 at US gauges?
Measured sea level rise at each gauge, and the rise NOAA’s 2022 interagency scenarios project by 2050 (cm above 2005). By 2050 the scenarios differ less than later in the century: much of the rise to 2050 is already set in motion.
| Gauge | Measured rise | 2050, Intermediate-Low | 2050, Intermediate | 2050, Intermediate-High | Flood days a year, 2050s |
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What drives this
- Sea-level rise →Higher baseline water turns ordinary high tides into floods.
- Hurricanes →Storm surge rides on top of the tide and the higher sea level.
- Ocean heat →Warmer water expands and raises sea level.
What this drives
- Long-term risk →Ice-sheet loss sets how high the sea goes after 2050.
How we know this
- Source: worldwide, hourly sea level from the University of Hawaiʻi Sea Level Center (fast-delivery data, about 1–2 months behind real time). In the US, NOAA’s Tides & Currents: live levels, tide predictions, flood thresholds, official flood counts, outlooks and projections.
- Update cadence: We check every night. The worldwide data arrives in monthly batches; NOAA’s live readings every night.
- Methods: For every gauge outside NOAA’s list we set the flood level the way NOAA does: average daily high tide plus 0.50 m plus 4% of the tide range, from the gauge’s own 2005–2014 tides. A flood day is a day the highest hourly reading reaches it. Checked against eight US gauges in both networks: the thresholds match NOAA’s to the millimetre (except Honolulu, where NOAA uses a local threshold).
- Uncertainty: Because our thresholds use 2005–2014 tides and NOAA’s use 1983–2001, our counts are lower than NOAA’s for the same place, but the change over time matches. Compare changes, not exact counts, between US and other gauges.
- Limitations: One gauge describes its harbour, not every street nearby. Gauge coverage is uneven: few in Europe, Africa and mainland Asia. Not a flood warning: follow your national weather service and local officials.
- Primary data: University of Hawaiʻi Sea Level Center · NOAA Tides & Currents · How this page is built