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Colin Park CC BY-SA 4.0 Wikimedia Commons

Clare Island

Island

Off County Mayo in Clew Bay, Clare Island attracts walkers, divers and birdwatchers. The island's 16th‑century castle links to Grace O'Malley; coastal cliffs, quiet trails and regular boat links from the mainland complete a visit.

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In this guide

Clare Island essentials

Address: Clare Island, County Mayo, Ireland

About Clare Island

Clare Island is an island at the mouth of Clew Bay off the west coast of County Mayo, Ireland, noted for its historical association with the 16th-century Gaelic leader Grace O’Malley and for its coastal habitats. It is one of a group of islands that frame Clew Bay.

Clare Island was the stronghold of the O’Malley seafaring clan in the medieval and early modern period; elements of defensive architecture and tower house ruins date to that era. The island’s maritime history continued into later centuries with lighthouses and coastal navigation.

Clare Island lies at the entrance to Clew Bay off County Mayo and is reached by booked ferry services from the mainland.

  • Access and services: Ferry services run seasonally from the County Mayo mainland and small visitor facilities are limited on the island, so check timetables and accommodation options in advance.
  • Practical tip: The island is known for both its archaeological sites and natural habitats; bring appropriate footwear for uneven trails around ruins and coastline.

What to See#

  • Grace O’Malley (Granuaile) castle ruins: Ruins of a 16th-century tower house associated with the sea‑raider and chieftain Grace O’Malley (Gráinne Ní Mháille), located near the island’s main harbour.
  • Coastal trails and wildlife areas: Coastal walking routes, sea cliffs and sheltered bays that are used for birdwatching and viewing marine life; the island contains a mix of coastal habitats and lowland pastures.
Things to Do
When to Go

Best Time to Visit Clare Island

Summer offers the most reliable boat services and the best conditions for hiking; shoulder seasons are worth it for fewer people.

Late spring-summer
May-August · 10-18°C
Cool, long days for walking paths and sea views; wildflowers and birdlife are active.
Autumn
September-October · 8-14°C
Quieter with storm-washed seas; fewer visitors but still accessible for most weather windows.

Weather & Climate near Clare Island

Climate

Clare Island's climate is classified as Oceanic - Oceanic climate with cool summers (peaking in August) and cold winters (coldest in February). Temperatures range from 3°C to 17°C. Abundant rainfall (1280 mm/year), wettest in January.

Air Quality: AQI 25 Good
Best Time to Visit
JuneJulyAugust
Temperature & Rainfall
Temperature Range
24°
Warmest Month
-1°
Coldest Month
Monthly Conditions
Month Comfort Temp Feels Rain Sky Humidity Wind UV Daylight
January Poor 4° - 9° 2° 148 mm overcast 86% 7.6 m/s 0.0 low 7.9h
February Poor 3° - 9° 2° 96 mm overcast 86% 7.4 m/s 0.1 low 9.6h
March Poor 4° - 9° 3° 105 mm overcast 85% 7.2 m/s 0.4 low 11.7h
April Acceptable 5° - 11° 5° 63 mm overcast 84% 6.1 m/s 0.8 moderate 13.8h
May Acceptable 7° - 14° 10° 72 mm overcast 84% 5.8 m/s 1.2 high 15.7h
June Good 9° - 15° 12° 72 mm overcast 85% 5.6 m/s 1.4 high 16.7h
July Good 11° - 17° 14° 79 mm overcast 86% 5.5 m/s 1.2 high 16.2h
August Acceptable 11° - 17° 14° 102 mm overcast 86% 5.5 m/s 1.0 moderate 14.6h
September Acceptable 10° - 16° 13° 119 mm overcast 85% 6.2 m/s 0.7 moderate 12.5h
October Poor 8° - 13° 10° 140 mm overcast 86% 6.8 m/s 0.3 low 10.4h
November Poor 5° - 10° 4° 142 mm overcast 86% 6.8 m/s 0.1 low 8.4h
December Poor 4° - 9° 3° 142 mm overcast 86% 7.2 m/s 0.0 low 7.3h
Getting There & Around

How to Get to Clare Island

Ferries run from Roonagh Pier (near Louisburgh) and from Rossaveal in better weather; the crossing time depends on the departure point (roughly 30-60 minutes). Private boats and seasonal services increase options during summer.

Tips for Visiting Clare Island

  • Book the island ferry in advance during summer weekends; slots can fill because of day-trippers from Westport or Roonagh.
  • Hire a local taxi-driver guide to reach Inishturk and the higher viewpoints-some tracks are steep and not well signed.
  • Visit Grace O'Malley's tower house (if open) and the small heritage trail that winds across the island-local guides add folklore and family histories.