Storms, Swell and Big Tides: When Swimmers Should Stay Out

If there is a Met Éireann wind, rain or coastal warning in force for your area, or the water looks rough, murky or unpredictable, do not swim. The Irish Coast Guard, RNLI and Water Safety Ireland put it directly in their January 2026 appeal: err on the side of caution and do not get in. A calm morning can become dangerous by afternoon.

Reading the forecasts takes about five minutes and is worth doing before every swim, not only in winter. The aim is to know the wind, the swell and the tide before you leave the house.

What the agencies say about storms

The January 2026 joint message says strong winds can bring very rough seas and large swells, that storm waters and rising sea levels can cut people off or send waves into normally dry areas with little or no time to escape, and that staying back from the water's edge can prevent a tragedy. For swimmers specifically, it says wind can worsen waves and swell, create rip currents and poor visibility, and increase cold exposure, and that strong winds make open water riskier even when the sky is clear.

The October 2024 message adds that recent bad weather had made seas less predictable, with large waves and swells, and that in severe weather people should keep a safe distance from exposed places such as cliffs, piers and beaches. It also warns of the danger from breaking waves, and advises checking weather forecasts, tide times and wave heights before going out so you are not stranded.

Reading Met Éireann warnings

Met Éireann's warnings use a colour system. A 2021 regional newspaper explainer, which you should check against met.ie because thresholds can change, describes the levels this way:

The same explainer gave wind thresholds for yellow of 50 to 65 km/h mean speeds, with gusts of 90 to 110 km/h, and described coastal wind warnings by Beaufort force: gale 8 or strong gale 9 at yellow, storm force 10 at orange, and violent storm force 11 or more at red. It also gave rain warning thresholds, for instance 30 to 50 mm in 24 hours at yellow. It states that warnings are normally issued for conditions expected within 48 hours, so check again on the morning of the swim, not just the day before.

Two things follow for swimmers. First, the wind warning is not the only one that matters: heavy rain affects water quality for at least 48 hours, as set out in bathing water quality in Ireland. Second, a swim can be unsafe with no warning at all. A strong onshore breeze below warning level can still produce dumping surf at a steep beach. Use the warning system as a floor, not a green light.

Marine and coastal forecasts

Met Éireann also publishes marine and coastal forecasts on met.ie. The format, the areas covered and the wording change from time to time, so read the explanation on the page itself rather than relying on a summary here. When you look, note three things: wind speed and direction at your site, expected swell or wave height, and when conditions are forecast to change. The Coast Guard and others say forecasts can change through the day, which is why a swim planned for the morning can still be wrong by the time you get there.

Wind direction matters because it decides how sheltered your beach is. An offshore wind can feel gentle at the shore while pushing a swimmer away from land, and an onshore wind builds the surf. Local swimmers who know the site are the best source on this, and Swim Ireland's open water guidance advises listening to officials on weather and water conditions.

Spring tides and big tides

The open water brochure hosted on cancer.ie says spring tides are more hazardous because they create stronger rip currents and raise the risk of getting stranded, and that swimming on a rising tide is much safer than on a falling one. Afloat.ie's 2016 piece quoting Irish Water Safety also links spring tides with weever fish stings, since they expose more sand near low water.

In practice, look up tide times and heights on a tide app or the tide tables for your port, then add these checks:

• Is it a spring tide, around new or full moon, with bigger rise and fall and faster flow? Take extra care at estuary mouths, channels between islands and harbour entrances.
• Will the beach be much steeper, rockier or narrower at low water than you remember?
• Is your exit a slipway or steps that go underwater at high water?
• Does the tide time overlap with the end of daylight? See dawn, dusk and night swimming safety.

A strong onshore wind against a falling spring tide is the sort of combination to avoid. Rip currents are covered in detail in sea swimming tides and currents in Ireland. The Coast Guard's advice for being caught in one is to stay calm, swim parallel to the shore to get out, and float to conserve energy if needed.

A go or no-go routine

1. Check Met Éireann warnings for your county and the sea area.
2. Check the marine forecast for wind, swell and changes through the day.
3. Check tide times, tide size and the state of the tide at your entry and exit.
4. Look at the water on arrival: breaking waves at the shore, rips, murky or foamy water, debris, and whether regulars are going in.
5. Decide with your group, and give anyone the right to say no without explanation.
6. If you go in, keep it short, stay near the shore, and keep a watcher on the beach.

Stormy days are also unsafe to watch from the shore. The January 2026 message warns that waves can reach normally dry areas, and that damaged paths and edges near the water may be unstable. See the cold water safety checklist for the full pre-swim list.