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M2 wave buoy daily means for May 2021

Daily means from the M2 wave buoy for May 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

727 wave-buoy observations covered all 31 days. Typical wave height was 2.1 ft (10th–90th percentile 1–6.7 ft), while mean peak wave period was 5.9 seconds (10th–90th percentile 3.4–8.4 seconds). Typical wind was 12 mph (10th–90th percentile 3.8–24.1 mph) and mean water temperature was 9.9°C (10th–90th percentile 9–11°C). 5 of 4,362 checked values (0.1%) were excluded by quality control. Across 9 comparable years, mean wave height was above the same-month mean of 2.9 ft and mean wave period was above the same-month mean of 5.1 seconds.

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

Typical Significant Wave Height

2.1ft
Mean: 3.1 ft
P10–P90: 1 — 6.7 ft
Recorded extremes

0 — 13.8 ft

Available for 726 of 727 hourly samples

Mean Observed Wave Period

5.9secs
P10–P90: 3.4 — 8.4secs
Recorded extremes

2.2 — 16.1secs

Available for 723 of 727 hourly samples

Typical Observed Wind

Variable, 12mph
Mean: 12.8 mph
P10–P90: 3.8 — 24.1 mph
Recorded extremes

0.2 — 37.3 mph

Circular concentration: 24%

Mean Water Temperature

9.9°C
P10–P90: 9 — 11°C
Recorded extremes

8.8 — 13.1°C

Compared With Previous Mays

Historical baseline from 6,640 observations across 9 years.

Wave Height
3.1ft
0.2ft above mean
Historical mean 2.887ft
Wave Period
5.9s
0.8s above mean
Historical mean 5.1s
Water Temperature
9.9°C
In line with the historical mean
Historical mean 9.9°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 May 2021Last observation shown
Metric
Mean significant wave height (ft)1167333566421122222874433212111
Mean maximum wave height (ft)1081044389862123332311116645322101
Mean peak period (s)4376545666777758663795685555686
Mean zero-crossing period (s)3355444555545545443564454434454
Mean peak wave directionNEconcentration 78%Variableconcentration 29%Sconcentration 97%NWconcentration 89%NNWconcentration 92%NNWconcentration 97%Nconcentration 50%SEconcentration 83%Sconcentration 99%Sconcentration 99%Sconcentration 99%Sconcentration 97%Sconcentration 89%SSEconcentration 82%SSEconcentration 80%Sconcentration 99%Variableconcentration 10%Sconcentration 74%WSWconcentration 68%Sconcentration 99%Variableconcentration 5%Nconcentration 86%Sconcentration 79%Sconcentration 87%NNWconcentration 50%NNWconcentration 46%Sconcentration 85%Sconcentration 98%SSEconcentration 81%SSEconcentration 85%SSEconcentration 71%
Mean wave directionNEconcentration 89%SSWconcentration 43%Sconcentration 99%NWconcentration 89%NNWconcentration 96%NNWconcentration 98%Nconcentration 51%SEconcentration 88%Sconcentration 100%Sconcentration 100%Sconcentration 99%SSEconcentration 96%SSEconcentration 97%SSEconcentration 86%SSEconcentration 94%Sconcentration 98%Variableconcentration 19%SSWconcentration 91%SWconcentration 78%Sconcentration 99%Variableconcentration 18%NNWconcentration 81%SSEconcentration 95%SSWconcentration 66%NNWconcentration 56%NNEconcentration 65%SSEconcentration 90%Sconcentration 99%SSEconcentration 87%SSEconcentration 95%SEconcentration 85%
Mean directional spread (°)33.335.724.427.333.526.735.229.422.023.425.726.026.823.830.222.127.930.129.221.130.235.327.226.036.740.037.333.833.233.830.8
Mean wind directionNNEconcentration 35%SWconcentration 61%SSWconcentration 82%NWconcentration 98%NWconcentration 97%NWconcentration 96%Wconcentration 39%SSEconcentration 79%Sconcentration 100%Sconcentration 98%SSEconcentration 90%SSEconcentration 63%NEconcentration 48%Variableconcentration 11%SEconcentration 83%Variableconcentration 20%Wconcentration 66%WSWconcentration 76%WSWconcentration 70%Sconcentration 96%NWconcentration 78%WNWconcentration 66%SSWconcentration 80%WNWconcentration 73%WNWconcentration 85%NWconcentration 55%Sconcentration 85%SSEconcentration 95%ESEconcentration 75%ENEconcentration 81%SEconcentration 90%
Mean wind speed (mph)572125151512212423155469712101326191617101491011459
Mean water temperature(°C)9.29.29.09.09.09.09.39.19.29.29.59.710.010.09.710.210.010.610.810.59.79.99.910.010.210.410.210.310.811.511.8

Swipe sideways to see more days.

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