Skip to content
Surfhog home
Menu

M2 wave buoy daily means for Sep 2025

Daily means from the M2 wave buoy for Sep 2025, 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

701 wave-buoy observations covered all 30 days. Typical wave height was 3.8 ft (10th–90th percentile 1.5–6.9 ft), while mean peak wave period was 5.7 seconds (10th–90th percentile 3.3–8.3 seconds). Typical wind was 17.6 mph (10th–90th percentile 7.6–27.6 mph) and mean water temperature was 15.1°C (10th–90th percentile 15–15.5°C). 13 of 3,848 checked values (0.3%) were excluded by quality control. Across 14 comparable years, mean wave height was above the same-month mean of 3.4 ft and mean wave period was above the same-month mean of 5.2 seconds.

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

Typical Significant Wave Height

3.8ft
Mean: 4 ft
P10–P90: 1.5 — 6.9 ft
Recorded extremes

0.8 — 10.4 ft

Mean Observed Wave Period

5.7secs
P10–P90: 3.3 — 8.3secs
Recorded extremes

2.6 — 15.4secs

Available for 699 of 701 hourly samples

Typical Observed Wind

SSW, 17.6mph
Mean: 17.3 mph
P10–P90: 7.6 — 27.6 mph
Recorded extremes

1.3 — 38.1 mph

Circular concentration: 43%

Mean Water Temperature

15.1°C
P10–P90: 15 — 15.5°C
Recorded extremes

0 — 15.8°C

Available for 332 of 701 hourly samples

Compared With Previous Septembers

Historical baseline from 9,184 observations across 14 years.

Wave Height
4ft
0.6ft above mean
Historical mean 3.412ft
Wave Period
5.7s
0.5s above mean
Historical mean 5.2s
Water Temperature
15.1°C
0.3°C above mean
Historical mean 14.8°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 Sep 2025Last observation shown
Metric
Mean significant wave height (ft)53333454655555QC rejected56453531223QC rejected22QC rejected
Mean maximum wave height (ft)844556869887791381078595233510337
Mean peak period (s)665845786655567577666433347695
Mean zero-crossing period (s)544544545544455455555433345444
Mean peak wave directionSSWconcentration 90%SSWconcentration 95%SSWconcentration 87%SSWconcentration 79%SWconcentration 78%SSEconcentration 98%SSEconcentration 98%Sconcentration 99%Sconcentration 98%Sconcentration 84%WSWconcentration 95%SWconcentration 84%SWconcentration 91%Sconcentration 80%WSWconcentration 75%Wconcentration 93%Sconcentration 97%Sconcentration 99%Sconcentration 97%Variableconcentration 19%Nconcentration 97%NNEconcentration 93%NNEconcentration 70%SEconcentration 83%ESEconcentration 85%SEconcentration 95%Sconcentration 98%SSWconcentration 68%Sconcentration 90%SSWconcentration 99%
Mean wave directionSSWconcentration 97%Sconcentration 97%SSWconcentration 93%SWconcentration 95%SWconcentration 90%SSEconcentration 97%SSEconcentration 98%SSWconcentration 98%Sconcentration 97%Sconcentration 82%WSWconcentration 98%SWconcentration 96%SWconcentration 97%Sconcentration 83%WSWconcentration 86%Wconcentration 89%Sconcentration 95%SSWconcentration 98%Sconcentration 98%Econcentration 33%Nconcentration 98%NNEconcentration 92%NEconcentration 75%SEconcentration 87%SEconcentration 92%SEconcentration 93%Sconcentration 98%SSWconcentration 87%Sconcentration 97%SSWconcentration 99%
Mean directional spread (°)135.6148.5124.683.9144.3163.7138.7118.2145.0158.6185.4166.6175.8137.2133.6170.9106.1110.6121.4141.2163.7185.4221.6210.2212.6209.9109.1143.298.4156.2
Mean wind directionSWconcentration 91%Sconcentration 79%SWconcentration 54%Wconcentration 97%SWconcentration 82%SEconcentration 95%Sconcentration 68%SWconcentration 83%SSEconcentration 94%Sconcentration 66%WSWconcentration 98%SWconcentration 94%WSWconcentration 93%Sconcentration 78%WSWconcentration 92%WSWconcentration 87%SSWconcentration 87%SSWconcentration 91%SSWconcentration 46%Nconcentration 94%Nconcentration 96%Nconcentration 98%NEconcentration 81%SEconcentration 88%SEconcentration 91%SEconcentration 94%SSWconcentration 50%Wconcentration 43%Sconcentration 64%Sconcentration 98%
Mean wind speed (mph)191012131619171724232322212232212116131621149109172161021
Mean water temperature(°C)15.115.315.415.415.415.315.115.215.215.215.115.115.115.112.2---------------

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