Celtic Sea water temperature

Celtic Sea, Ballycotton · Sea/Coast

The current water temperature at Celtic Sea is 17.0 °C (as of September 1, 2026, source: official monitoring networks).

The sea lags the air by weeks: the warmest water often arrives after the warmest days. Measured buoy values show this honestly.

17.0 °C

Measured: September 1, 2026 · continuously updated

💧 Water 17.0° · ☀️ Air 17.6°

Temperature trend of recent weeks

Celtic Sea — Photo: Mark Devine from Dublin, Ireland · CC BY-SA 2.0 · Wikimedia Commons

Measurement series & statistics

This measurement series includes 1418 data points since July 3, 2026.

Lowest recorded value: 12.5 °C on July 6, 2026 · highest value: 22.1 °C on July 16, 2026.

In September, temperatures have ranged between 17.0 °C and 17.4 °C.

The current value is 0.2 °C below the September average of this series.

Nearby waters

Kilta, Killamucky · 11.9 km away13.5 °C Owennacurra, Bailick Road · 14.3 km away20.8 °C Dungourney, Midleton Town Park · 14.7 km away13.7 °C Dungourney, Dungourney Bridge · 16.9 km away13.7 °C Youghal Harbour, Youghal Quay · 17.8 km away17.2 °C

More measuring points: Celtic Sea

Booby'S Bay22.5 °C Constantine Bay Beach22.2 °C Harlyn Bay Beach22.2 °C Pendower Beach22.0 °C Mother Ivey'S Bay21.9 °C Swanpool Beach21.8 °C

Frequently asked questions

Can you swim at Celtic Sea right now?
The current water temperature is 17.0 °C. See live swimming conditions, weather and quality in the BrrChecker app.

How warm is the water at Celtic Sea?
Currently 17.0 °C (updated continuously).

How warm is at Celtic Sea in September?
In September, the water temperature recently averaged 17.2 °C.

When is the water warmest at Celtic Sea?
Across the measurement record, July is on average the warmest month (17.5 °C).

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