Warnings on the sea water level

On the basis of the sea water level observations made, the warning limits have been set so that the frequency of warnings at the lowest risk level (yellow) is once a year, at the second risk level (orange) once in five years, and at the highest risk level (red) once in 20 years.

Only one warning level is used for low water (yellow), but all three warning levels are used for high water (yellow, orange and red). The warning levels are set for the 14 observation stations.

Warnings for sea level are drawn up for periods of up to 5 days.

Sea level warning limits

The warning limits are listed in the tables below referenced to the theoretical mean water (MW) and N2000 (BSCD2000) systems.

Theoretical mean water (MW)

  low
(yellow)
high
(yellow)
very high
(orange)
dangerously high (red)
Kemi, Oulu -80 cm 115 cm 140 cm 170 cm
Raahe, Pietarsaari -65 cm 85 cm 110 cm 130 cm
Vaasa -50 cm 85 cm 110 cm 130 cm
Kaskinen, Pori, Rauma -50 cm 75 cm 100 cm 120 cm
Föglö -50 cm 65 cm 85 cm 100 cm
Turku, Hanko -50 cm 70 cm 95 cm 110 cm
Helsinki, Porvoo -60 cm 80 cm 115 cm 130 cm
Hamina -70 cm 110 cm 145 cm 170 cm

N2000 (BSCD2000)

  low
(yellow)
high
(yellow)
very high
(orange)
dangerously high (red)
Kemi, Oulu -71 cm 124 cm 149 cm 179 cm
Raahe -56 cm  94 cm 119 cm 139 cm
Pietarsaari -58 cm  92 cm 117 cm 137 cm
Vaasa -43 cm  92 cm 117 cm 137 cm
Kaskinen -40 cm  85 cm 110 cm 130 cm
Pori, Rauma -38 cm  87 cm 112 cm 132 cm
Föglö -39 cm  76 cm  96 cm 111 cm
Turku -35 cm  85 cm 110 cm 125 cm
Hanko -32 cm  88 cm 113 cm 128 cm
Helsinki, Porvoo -39 cm 101 cm 136 cm 151 cm
Hamina -49 cm 131 cm 166 cm 191 cm

 

A man standing in the flood water.
Flooding. Photo: Eija Vallinheimo

15.9.2021