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M2 wave buoy daily means for Dec 2021

Daily means from the M2 wave buoy for Dec 2021, including available wave height, period, direction, wind and sea temperature data.

Last observation shown

Data available:  to 

Monthly means for

Latest

Period Summary

Programmatically generated summary. Hog Says

498 wave-buoy observations covered 21 of 31 days (68%). Typical wave height was 4.1 ft (10th–90th percentile 1.5–8.7 ft), while mean peak wave period was 5.5 seconds (10th–90th percentile 3.6–7.2 seconds). Typical wind was 18.2 mph (10th–90th percentile 7.4–31.7 mph) and mean water temperature was 12.1°C (10th–90th percentile 11.6–12.4°C). All 2,988 checked values passed quality control. Across 11 comparable years, mean wave height was below the same-month mean of 5.7 ft and mean wave period was below the same-month mean of 6.1 seconds.

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

Typical Significant Wave Height

4.1ft
Mean: 4.8 ft
P10–P90: 1.5 — 8.7 ft
Recorded extremes

1 — 21 ft

Mean Observed Wave Period

5.5secs
P10–P90: 3.6 — 7.2secs
Recorded extremes

2.5 — 11.7secs

Typical Observed Wind

WSW, 18.2mph
Mean: 19.1 mph
P10–P90: 7.4 — 31.7 mph
Recorded extremes

1.3 — 46 mph

Circular concentration: 37%

Mean Water Temperature

12.1°C
P10–P90: 11.6 — 12.4°C
Recorded extremes

11.3 — 12.5°C

Compared With Previous Decembers

Historical baseline from 7,063 observations across 11 years.

Wave Height
4.8ft
0.9ft below mean
Historical mean 5.741ft
Wave Period
5.5s
0.6s below mean
Historical mean 6.1s
Water Temperature
12.1°C
0.6°C above mean
Historical mean 11.5°C

Chart showing grouped wave observations for M2. Use the table on this page for a text version of the same measurements. To open hourly observations, use a linked day 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; days run left to right.
M2 wave buoy daily means Dec 2021Last observation shown
Metric
Mean significant wave height (ft)75376611QC rejected5646434212232----------
Mean maximum wave height (ft)1175109817157958646313242----------
Mean peak period (s)655665875557856555454----------
Mean zero-crossing period (s)544555664445544434343----------
Mean peak wave directionNNWconcentration 89%NNWconcentration 63%WSWconcentration 53%WNWconcentration 91%Nconcentration 90%SWconcentration 67%SSWconcentration 83%Wconcentration 90%WSWconcentration 71%WNWconcentration 98%SSWconcentration 79%Sconcentration 95%Sconcentration 100%Sconcentration 94%Sconcentration 99%Sconcentration 95%SSEconcentration 70%ENEconcentration 92%ENEconcentration 85%Econcentration 94%SSEconcentration 75%----------
Mean wave directionNWconcentration 92%NNWconcentration 68%WSWconcentration 73%WNWconcentration 90%Nconcentration 92%SWconcentration 75%Sconcentration 91%Wconcentration 93%WSWconcentration 79%Wconcentration 99%SSWconcentration 90%Sconcentration 100%Sconcentration 99%SSWconcentration 99%Sconcentration 100%Sconcentration 99%SSEconcentration 89%Econcentration 99%Econcentration 98%Econcentration 94%SSEconcentration 95%----------
Mean directional spread (°)26.130.238.125.430.628.827.727.327.126.825.421.222.823.223.631.040.529.129.927.546.0----------
Mean wind directionNWconcentration 92%NWconcentration 65%Wconcentration 88%WNWconcentration 95%NNWconcentration 75%WSWconcentration 84%SSWconcentration 80%WNWconcentration 98%Wconcentration 82%WNWconcentration 99%SWconcentration 91%SSWconcentration 89%WSWconcentration 79%SSWconcentration 98%SWconcentration 98%SSWconcentration 91%ESEconcentration 90%ENEconcentration 60%NEconcentration 97%Econcentration 77%SSEconcentration 98%----------
Mean wind speed (mph)28191830202632362424192281716999101411----------
Mean water temperature(°C)12.412.312.312.212.112.012.012.412.412.412.312.312.312.212.112.011.811.711.611.511.6----------

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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.

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