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M2 wave buoy monthly means for 2004

Monthly means from the M2 wave buoy for 2004, including available wave height, period, direction, wind and sea temperature data.

Last observation shown

Data available:  to 

Latest

Period Summary

Programmatically generated summary. Hog Says

7,712 wave-buoy observations covered 343 of 366 days (94%). Typical wave height was 3.9 ft (10th–90th percentile 1.6–7.5 ft), while mean zero-crossing wave period was 4.8 seconds (10th–90th percentile 4–6 seconds). Typical wind was 16.1 mph (10th–90th percentile 6.9–27.6 mph) and mean water temperature was 11.6°C (10th–90th percentile 8.5–14.3°C). 3 of 36,697 checked values (0%) were excluded by quality control.

Generated only from the observations and comparisons shown on this page.

Typical Significant Wave Height

3.9ft
Mean: 4.3 ft
P10–P90: 1.6 — 7.5 ft
Recorded extremes

0.7 — 13.8 ft

Available for 6,887 of 7,712 hourly samples

Mean Observed Wave Period

4.8secs
P10–P90: 4 — 6secs
Recorded extremes

3 — 9secs

Available for 7,147 of 7,712 hourly samples

Typical Observed Wind

WSW, 16.1mph
Mean: 17 mph
P10–P90: 6.9 — 27.6 mph
Recorded extremes

2.3 — 42.6 mph

Circular concentration: 35%

Available for 7,488 of 7,712 hourly samples

Mean Water Temperature

11.6°C
P10–P90: 8.5 — 14.3°C
Recorded extremes

7.9 — 16.3°C

Available for 7,571 of 7,712 hourly samples

Chart showing grouped wave observations for M2. Use the table on this page for a text version of the same measurements. To open daily observations, use a linked month name in the table.

About M2 wave buoy

M2 (WMO 62091) is part of the Irish Marine Data Buoy Observation Network, managed by the Marine Institute in collaboration with Met Éireann. Moored in the Irish Sea east of Ireland, it provides open-water context for the busy, relatively enclosed waters between the Irish and British coasts.

Its current data source reports wave height, wave period, wave direction, directional spread, wind conditions and sea temperature.

Metrics are rows; months run left to right.
M2 wave buoy monthly means 2004Last observation shown
Metric
Mean significant wave height (ft)6555233-5545
Mean maximum wave height (ft)------------
Mean peak period (s)------------
Mean zero-crossing period (s)5555444-5555
Mean peak wave direction------------
Mean wave direction------------
Mean directional spread (°)------------
Mean wind directionWSWconcentration 65%Variableconcentration 14%SWconcentration 31%SWconcentration 35%Variableconcentration 25%WSWconcentration 54%WSWconcentration 47%SEconcentration 49%SWconcentration 47%Variableconcentration 13%Wconcentration 55%WSWconcentration 61%
Mean wind speed (mph)22181717111513919202022
Mean water temperature(°C)10.29.18.48.710.612.613.114.214.514.113.111.8

Swipe sideways to see more months.

Wave metric colour key

Colours move through the scale as each number increases. They do not by themselves mean that conditions are good, safe or suitable for you.

Wave & swell height0–40+ ft
Wave & swell period0–22+ s
Wind speed0–75 mph

The displayed numbers remain the source of truth; colour is an additional visual cue.

What does buoy wave power mean?

kW/m means kilowatts of wave power per metre of wave crest. It describes the rate at which the observed sea state carries energy past the buoy.

Unlike the shore-directed forecast value, buoy wave power is the total power at the observation point. It is not projected towards a particular beach and does not predict breaking wave height.

In deep water, wave power can be calculated with:

P is approximately 0.49 times significant wave height squared times wave energy period.

P is power in kW/m, Hs is significant wave height in metres, and Te is wave energy period in seconds.

  • Provider-reported power is used when available.
  • Otherwise, a value is calculated only when both significant height and a genuine energy period are available. The ≈ symbol marks calculated values.
  • A dash is shown instead of substituting peak, Tm02, zero-crossing or other period measurements.
  • Daily and monthly figures use the mean of hourly-normalized observation power values; they are not calculated from mean height and period.

Wave direction, spectrum, water depth and local bathymetry still matter. Wave power is best read alongside height, period and direction rather than as a standalone surf-quality score.

The observation data displayed on this page is from the Met Éireann Irish Marine Data Buoy Observation Network.

Learn how SurfHog combines, checks and summarizes observations in the data and methodology notes.

› Wave Buoy List