Portmarnock
Ireland
Long-term weather forecast
Long-term weather forecast

Monthly weather forecast and climate
Portmarnock, Ireland

In January, the average sea temperature in Portmarnock, Ireland, is 9.6°C (49.3°F). Note: At temperatures below 10°C (50°F), swimming in a suitably protected swimsuit is feasible; otherwise, cold shock and loss of breathing control are imminent. Weather in January »

In Portmarnock, Ireland, in February, the average water temperature is 8.8°C (47.8°F). Note: Swimming in 8.8°C (47.8°F) is considered dangerous. Unprotected immersion in temperatures below 10°C (50°F) causes quickly maximum intensity cold shock with hyperventilation. Weather in February »

With an average sea temperature of 8.4°C (47.1°F), March is the month with the coldest seawater in Portmarnock, Ireland. Note: At temperatures below 10°C (50°F), swimming in a suitably protected swimsuit is feasible; otherwise, cold shock and loss of breathing control are imminent. Weather in March »

In April, the average sea temperature in Portmarnock, Ireland, is 9.2°C (48.6°F). Note: Swimming in 9.2°C (48.6°F) is considered life-threatening. Even a few minutes in 13°C (55.4°F) water is uncomfortable, and swimming below 10°C (50°F) may cause total loss of breathing control and cold shock, depending on a person's physique. Weather in April »

In May, the average sea temperature in Portmarnock, Ireland, is 10.4°C (50.7°F). Note: At temperatures below 10°C (50°F), swimming in a suitably protected swimsuit is feasible; otherwise, cold shock and loss of breathing control are imminent. Weather in May »

In June, the average sea temperature in Portmarnock, Ireland, is 12.3°C (54.1°F). Note: Swimming in 12.3°C (54.1°F) is considered dangerous. Unprotected immersion in temperatures below 10°C (50°F) causes quickly maximum intensity cold shock with hyperventilation. Weather in June »

In Portmarnock, Ireland, in July, the average water temperature is 14.1°C (57.4°F). Note: Swimming in 14.1°C (57.4°F) is considered dangerous. Unprotected immersion in temperatures below 10°C (50°F) causes quickly maximum intensity cold shock with hyperventilation. Weather in July »

With an average sea temperature of 14.9°C (58.8°F), August is the month with the warmest seawater in Portmarnock, Ireland. Note: Swimming in 14.9°C (58.8°F) is considered life-threatening. Weather in August »

In Portmarnock, Ireland, in September, the average water temperature is 14.8°C (58.6°F). Note: Swimming in 14.8°C (58.6°F) is considered life-threatening. Weather in September »

In Portmarnock, Ireland, in October, the average water temperature is 14.1°C (57.4°F). Note: Swimming in 14.1°C (57.4°F) is considered dangerous. Unprotected immersion in temperatures below 10°C (50°F) causes quickly maximum intensity cold shock with hyperventilation. Weather in October »

In Portmarnock, Ireland, in November, the average water temperature is 13.1°C (55.6°F). Note: Swimming in 13.1°C (55.6°F) is considered dangerous. Unprotected immersion in temperatures below 10°C (50°F) causes quickly maximum intensity cold shock with hyperventilation. Weather in November »

In December, the average sea temperature in Portmarnock, Ireland, is 11.3°C (52.3°F). Note: Swimming in 11.3°C (52.3°F) is considered life-threatening. Even a few minutes in 13°C (55.4°F) water is uncomfortable, and swimming below 10°C (50°F) may cause total loss of breathing control and cold shock, depending on a person's physique. Weather in December »

What month is the sea coldest in Portmarnock?

The month with the coldest seawater in Portmarnock, Ireland, is March, with an average sea temperature of 8.4°C (47.1°F).

When are the longest days in Portmarnock?

The month with the longest days in Portmarnock is June, with an average of 16.9h of daylight.

When is the sea warmest in Portmarnock?

August is the month with the warmest seawater in Portmarnock, with an average sea temperature of 14.9°C (58.8°F).

What is the month with the shortest days in Portmarnock?

The month with the shortest days in Portmarnock, Ireland, is December, with an average of 7.6h of daylight.
Average sea temperature - Portmarnock, Ireland

The best month for swimming (with the highest average sea temperature) is August (14.9°C).
The coldest month (with the lowest average sea temperature) is March (8.4°C).

Average daylight - Portmarnock, Ireland

The month with the longest days is June (Average daylight: 16.9h).
The month with shortest days is December (Average daylight: 7.6h).