October 4, 1755 Tsunami: Lake Ontario, United States
A tsunami of unknown cause began at Lake Ontario, United States on October 4, 1755. The water rose as high as 1.52 meters. Its effects were recorded at 1 place.
Where the waves reached
The source (white) and every runup with a place, colored by the water height recorded there. A ring is a runup NCEI marks doubtful.
- Under 1 m
- 1 to 3 m
- 3 to 10 m
- 10 to 30 m
- 30 m and more
- Height not recorded
The tsunami
- Date
- October 4, 1755
- Source
- Lake Ontario, United States
- Cause
- Unknown
- Maximum water height
- 1.52 m (5.0 ft)
- Runups recorded
- 1
- Waters
- A lake or river, not the ocean
- How certain
- Questionable tsunami
- Source location
- 43.500° N, 78.000° W
The toll
The record gives no deaths, injuries or damage for this tsunami.
What the record says
NCEI’s account, from the sources it cites.
1755, October 4? In Lake Ontario between 10:00 and 11:00 A.M. the water repeatedly rose in an unusual way to the height of five feet. No shock is mentioned. (Dawson, 1860; Mallet, 1851) Validity 2. [unknown cause] (reference #541)
1755 Oct. CANADA.-No shocks, but unusual rise and fall of water in Lake Ontario. (reference #1715)
1755 in first half of October. Lake Ontario. No shock is mentioned but the water repeatedly rose in an unusual way to the height of five feet. (reference #521)
[…] on Lake Ontario, strong agitations of the water were observed in October, 1755. (reference #13438)
Reference #12345 lists as validity 1 with meteorological source. (accessed August 2024)
Every runup
Nearest the source first. Heights are above sea level at the time; a tide gauge reads half the wave’s full height.
| Where | Country | Km from source | Water height, m | Inland, m | Measured by | First wave, UTC | Deaths |
|---|---|---|---|---|---|---|---|
| Lake Ontario, NY, NY | United States | 0 | 1.52 | Eyewitness observation of water height |
More
Every tsunami in 1755The 1700sTsunamis of United StatesThis day in weather historyAlerts in force
Sources
Tsunami events and runups from NOAA’s National Centers for Environmental Information, Global Historical Hazard Database, cited as NCEI/WDS, doi:10.7289/V5PN93H7. Public domain. Read 2026-09-24. NCEI tsunami event 2441.