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Andreas F. Borchert CC BY-SA 4.0 Wikimedia Commons

Lough Allen

Lake

Part of the upper River Shannon system, Lough Allen spans the northwest Irish landscape; visitors come for kayaking, angling, cycling routes and quiet lakeside accommodation.

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In this guide

Lough Allen essentials

Address: Lough Allen, counties Leitrim/Longford/Roscommon, Ireland
Hours: Public access (24 hours)
Admission: Free (public water)
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About Lough Allen

Lough Allen is a freshwater lake on the upper course of the River Shannon in northwest Ireland. It is one of the principal lakes in the Shannon basin and forms part of the river’s headwaters.

The lake is frequented for boating, fishing and shoreline walking, with a patchwork of small bays and islands that attract local outdoor recreation. Facilities and access points are modest and typically oriented to small boats and anglers.

Lough Allen is a glacially formed lake that has been part of inland transport and local economies along the Shannon since historic times. Its shoreline settlements developed around fishing and small-scale agriculture.

The lake lies within the Shannon basin in northwest Ireland, straddling parts of the surrounding counties and set among low hills and agricultural land in the region.

  • Navigation and recreation: The lake forms part of the upper River Shannon system and is used for recreational boating and angling; local conditions can change quickly so check with local harbours or clubs before heading out.
When to Go

Best Time to Visit Lough Allen

Summer and early autumn provide the best conditions for boating and fishing; winter is quieter and can be used for ice activities if conditions permit.

Summer
June-August · 15-22°C (59-72°F)
Pleasant for boating and fishing, and the lake is busiest with recreational users.
Autumn
September-October · 8-15°C (46-59°F)
Quieter with good light for photography and birdwatching.

Weather & Climate near Lough Allen

Climate

Lough Allen's climate is classified as Oceanic - Oceanic climate with mild summers (peaking in July) and cold winters (coldest in January). Temperatures range from 2°C to 18°C. Abundant rainfall (1211 mm/year), wettest in January.

Air Quality: AQI 26 Good
Best Time to Visit
JulyJuneAugust
Temperature & Rainfall
Temperature Range
27°
Warmest Month
-7°
Coldest Month
Monthly Conditions
Month Comfort Temp Feels Rain Sky Humidity Wind UV Daylight
January Poor 3° - 8° 2° 129 mm overcast 95% 4.2 m/s 0.0 low 7.7h
February Poor 3° - 8° 2° 98 mm overcast 94% 4.2 m/s 0.1 low 9.5h
March Poor 4° - 9° 4° 104 mm overcast 91% 4.2 m/s 0.3 low 11.7h
April Acceptable 5° - 12° 6° 71 mm overcast 87% 3.7 m/s 0.7 moderate 13.9h
May Acceptable 7° - 15° 11° 71 mm overcast 85% 3.6 m/s 1.1 high 15.8h
June Good 10° - 17° 13° 77 mm overcast 84% 3.4 m/s 1.3 high 16.9h
July Good 12° - 18° 15° 81 mm overcast 86% 3.3 m/s 1.2 high 16.4h
August Good 12° - 18° 15° 101 mm overcast 87% 3.1 m/s 0.9 moderate 14.7h
September Acceptable 10° - 16° 13° 101 mm overcast 89% 3.3 m/s 0.6 moderate 12.5h
October Acceptable 8° - 13° 10° 127 mm overcast 92% 3.6 m/s 0.2 low 10.3h
November Poor 5° - 10° 5° 126 mm overcast 95% 3.6 m/s 0.1 low 8.3h
December Poor 4° - 9° 3° 125 mm overcast 95% 3.8 m/s 0.0 low 7.1h
Getting There & Around

How to Get to Lough Allen

Drive via the N4 and local regional roads (R280). Towns such as Drumshanbo and Carrick-on-Shannon provide bases for exploring the lake; small marinas and boat rental services operate seasonally.

Tips for Visiting Lough Allen

  • Explore the shoreline by kayak or small boat to reach quieter bays and birding sites.
  • Drive the R280 and local roads for scenic viewpoints along the lake's rim.
  • Visit in winter if interested in ice fishing; local operators provide equipment and guidance.