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M2 wave buoy monthly means for 2021

Monthly means from the M2 wave buoy for 2021, 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

8,404 wave-buoy observations covered 355 of 365 days (97%). Typical wave height was 2.6 ft (10th–90th percentile 1–7.2 ft), while mean peak wave period was 5.4 seconds (10th–90th percentile 3.3–8 seconds). Typical wind was 14.2 mph (10th–90th percentile 5.4–25.4 mph) and mean water temperature was 12°C (10th–90th percentile 8.4–15.6°C). 57 of 50,424 checked values (0.1%) were excluded by quality control.

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

Typical Significant Wave Height

2.6ft
Mean: 3.5 ft
P10–P90: 1 — 7.2 ft
Recorded extremes

0 — 21 ft

Available for 8,400 of 8,404 hourly samples

Mean Observed Wave Period

5.4secs
P10–P90: 3.3 — 8secs
Recorded extremes

2 — 18.3secs

Available for 8,351 of 8,404 hourly samples

Typical Observed Wind

Variable, 14.2mph
Mean: 15.1 mph
P10–P90: 5.4 — 25.4 mph
Recorded extremes

0.2 — 46.2 mph

Circular concentration: 21%

Mean Water Temperature

12°C
P10–P90: 8.4 — 15.6°C
Recorded extremes

7.9 — 19.3°C

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 2021Last observation shown
Metric
Mean significant wave height (ft)464232222545
Mean maximum wave height (ft)695343233767
Mean peak period (s)685565555656
Mean zero-crossing period (s)454444444444
Mean peak wave directionVariableconcentration 8%SSEconcentration 73%Variableconcentration 27%Variableconcentration 28%Sconcentration 37%Variableconcentration 11%Variableconcentration 15%Variableconcentration 27%Sconcentration 38%SSWconcentration 55%Wconcentration 35%Variableconcentration 26%
Mean wave directionVariableconcentration 12%SSEconcentration 76%Sconcentration 33%Variableconcentration 28%Sconcentration 39%Variableconcentration 17%Variableconcentration 22%Sconcentration 33%Sconcentration 49%SSWconcentration 58%Wconcentration 40%SSWconcentration 32%
Mean directional spread (°)27.827.528.231.629.629.631.529.731.726.628.228.8
Mean wind directionVariableconcentration 23%SSEconcentration 61%WSWconcentration 39%Variableconcentration 24%Variableconcentration 24%Variableconcentration 6%Variableconcentration 1%Variableconcentration 21%SSWconcentration 31%SWconcentration 63%Wconcentration 61%WSWconcentration 37%
Mean wind speed (mph)18211612131391211191919
Mean water temperature(°C)9.68.58.48.89.912.115.515.515.514.513.712.1

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