SPRING 2021: When you may experience higher than normal tides
between March and May, 2021.
Tides are the regular rise and
fall of the sea surface caused by the gravitational pull of the moon and sun and their position relative to
the earth. There are some factors that cause the tides to be higher than what is "normally" seen from day to
day. Depending on non-tidal conditions (wind, storms, etc.), regions may experience impacts before or after
the dates mentioned here.
Higher than normal high tides alone do not necessarily cause coastal flooding. However, they are becoming
increasingly impactful due to continued sea level rise. High tide
flooding that inundates busy streets, and
washes out beaches is more likely to occur during these periods depending on your location along the coast.
More severe flooding may result if adverse weather—heavy rains, strong wind or big waves—conditions are
Want to dig deeper? View the latest annual report
high tide flooding events in 2019 and our high tide flooding outlook through April 2021.
This report is based on new, national flooding thresholds. It focuses on more impactful, deeper floods at some locations and
expands the outlook to about 100 coastal locations.
Select your region to see when you may experience higher than normal tides that may cause flooding.
The NOAA Coastal Inundation Dashboard provides real-time water levels with forecasts out to 48 hours for all tidal stations.
View an archive of past high tide flooding dates for all regions.
CO-OPS is the NOAA tides and currents office.
Maine, New Hampshire, Massachusetts, Rhode Island, Connecticut, and New York
March 29 - April 2, 2021
April 26 - May 1, 2021
May 24 - May 30, 2021 (The predicted tides at some locations will
be some of the highest of the year)
Tide stations at the following locations have the greatest chance of seeing high tide
Bar Harbor, Maine; Portland, Maine; Boston, Massachusetts; Providence, Rhode Island; Kings Point, New York
A perigean spring tide will be occurring. This is when the
moon is either new or full and closest to earth. Higher than normal high tides and lower than normal low tides
Tides will increase leading up to and after the June 21
summer solstice, due to the position of the sun relative to the earth's equator.
Mean sea level is typically higher in the late spring due to
patterns and increasing water temperatures.
What kind of impact might I expect along the coast?
Due to the topography, in particular for southeast Alaska (less low lying areas), tidal flooding will generally not have a significant impact on the coast unless there is a severe storm. Lower than normal low tides will also occur.
Lower than normal low tides will also occur.
Coastal Inundation Dashboard
View real-time and historic coastal flooding information.