Slemish

Mountain Volcanic hill associated with St Patrick pilgrimage

Slemish rises east of Ballymena as a steep basalt plug long associated with St. Patrick. Visitors climb the well‑worn path for panoramic views and modest memorials at the summit.

Main image

Slemish is a distinctive volcanic plug rising above the surrounding plain in County Antrim, Northern Ireland, and is a well-known local landmark. The hill is traditionally associated with St. Patrick and is a frequent destination for short walks and local pilgrimages.

The usual visitor experience is a steep but well-defined footpath to the summit, which provides broad views across the Antrim countryside and, on clear days, toward the north coast. The route is a relatively short, strenuous hike rather than a long mountain walk.

Geologically the hill is the remnant of ancient volcanic activity and over time has remained as a solitary, conical feature in the landscape. It has cultural associations through its link to St. Patrick that have shaped local use and commemorations.

Slemish stands northeast of Ballymena in County Antrim, rising clearly above surrounding farmland and visible from a wide area of mid-Antrim.

  • Geology and walk: The hill is a distinctive volcanic plug and a prominent landmark in County Antrim with a popular steep walking route to the top.

What to See #

  • Summit route: The summit cone reached by a steep, waymarked footpath that is the usual objective for walkers and pilgrims.
  • Lower slopes and trailheads: Lower slopes and agricultural land encircling the hill, where parking and the main trailheads are located and views open toward the Antrim coast on clear days.
Slemish
Slemish Mountain, County Antrim, Northern Ireland
54.8833, -6.1167

How to Get to Slemish #

Slemish is about 10 km north of Ballymena in County Antrim. From Ballymena town centre, drive or take local taxis toward the Slemish road (B94 area); there is a small car park at the trailhead with an approach path to the climb.

Tips for Visiting Slemish #

  • Start early to avoid warm afternoon mist and to have the summit to oneself for sunrise views.
  • Wear waterproof boots-the trail can be boggy in places, especially after rain.

Best Time to Visit Slemish #

Best in late spring through early autumn for walking; avoid boggy conditions after heavy rain.

Spring/Summer
May-August · 10-18°C (50-64°F)
Pleasant walking weather and clear views; peak grazing season for local farms.
Autumn
September-October · 8-15°C (46-59°F)
Crisp air and fewer visitors; scenic colors on the lower slopes.

Weather & Climate near Slemish #

Climate

Slemish's climate is classified as Oceanic - Oceanic climate with cool summers (peaking in July) and cold winters (coldest in January). Temperatures range from 1°C to 18°C. Abundant rainfall (1127 mm/year), wettest in January.

Best Time to Visit
JuneJulyAugust
Temperature & Rainfall
Temperature Range
24°
Warmest Month
-2°
Coldest Month
Monthly Conditions

January

January is the coolest month with highs of 6°C and lows of 1°C. The wettest month with heavy rain (121 mm), mostly overcast skies, and breezy conditions.

38 Poor

Comfort

Feels Like Cold
C
Temperature
91%
Humidity
Very Humid

Weather

121 mm
Rainfall
6.3 m/s
Wind
Breezy
0.0
UV Index
Low
7.7h daylight

February

February is cold with highs of 7°C and lows of 1°C. Regular rainfall (88 mm), mostly overcast skies, and breezy conditions.

40 Poor

Comfort

Feels Like Cold
C
Temperature
90%
Humidity
Very Humid

Weather

88 mm
Rainfall
6.3 m/s
Wind
Breezy
0.1
UV Index
Low
9.5h daylight

March

March is cold with highs of 8°C and lows of 2°C. Regular rainfall (98 mm), mostly overcast skies, and breezy conditions.

40 Poor

Comfort

Feels Like Cold
C
Temperature
88%
Humidity
Very Humid

Weather

98 mm
Rainfall
6.0 m/s
Wind
Breezy
0.3
UV Index
Low
11.7h daylight

April

April is cold with highs of 11°C and lows of 3°C. Moderate rainfall (70 mm) and mostly overcast skies.

54 Acceptable

Comfort

Feels Like Cold
C
Temperature
11°
86%
Humidity
Very Humid

Weather

70 mm
Rainfall
5.1 m/s
Wind
Light Breeze
0.7
UV Index
Moderate
13.9h daylight

May

May is cold with highs of 14°C and lows of 6°C. Moderate rainfall (63 mm) and mostly overcast skies.

56 Acceptable

Comfort

10°
Feels Like Cold
10°C
Temperature
14°
84%
Humidity
Very Humid

Weather

63 mm
Rainfall
4.8 m/s
Wind
Light Breeze
1.0
UV Index
Moderate
15.8h daylight

June

June is cool with highs of 16°C and lows of 8°C. Moderate rainfall (66 mm) and mostly overcast skies.

62 Good

Comfort

12°
Feels Like Cool
12°C
Temperature
16°
85%
Humidity
Very Humid

Weather

66 mm
Rainfall
4.4 m/s
Wind
Light Breeze
1.2
UV Index
High
16.9h daylight

July

July is cool with highs of 18°C and lows of 11°C. Moderate rainfall (76 mm) and mostly overcast skies.

60 Good

Comfort

14°
Feels Like Cool
14°C
Temperature
11° 18°
86%
Humidity
Very Humid

Weather

76 mm
Rainfall
4.3 m/s
Wind
Light Breeze
1.1
UV Index
High
16.4h daylight

August

August is cool with highs of 18°C and lows of 10°C. Regular rainfall (91 mm) and mostly overcast skies.

60 Good

Comfort

14°
Feels Like Cool
14°C
Temperature
10° 18°
87%
Humidity
Very Humid

Weather

91 mm
Rainfall
4.3 m/s
Wind
Light Breeze
0.9
UV Index
Moderate
14.7h daylight

September

September is cool with highs of 15°C and lows of 8°C. Significant rainfall (101 mm) and mostly overcast skies.

58 Acceptable

Comfort

12°
Feels Like Cool
12°C
Temperature
15°
87%
Humidity
Very Humid

Weather

101 mm
Rainfall
4.8 m/s
Wind
Light Breeze
0.5
UV Index
Moderate
12.5h daylight

October

October is cold with highs of 12°C and lows of 6°C. Significant rainfall (119 mm) and mostly overcast skies.

50 Acceptable

Comfort

Feels Like Cold
C
Temperature
12°
89%
Humidity
Very Humid

Weather

119 mm
Rainfall
5.6 m/s
Wind
Light Breeze
0.2
UV Index
Low
10.3h daylight

November

November is cold with highs of 9°C and lows of 3°C. Significant rainfall (118 mm) and mostly overcast skies.

42 Poor

Comfort

Feels Like Cold
C
Temperature
90%
Humidity
Very Humid

Weather

118 mm
Rainfall
5.7 m/s
Wind
Light Breeze
0.1
UV Index
Low
8.3h daylight

December

December is cold with highs of 7°C and lows of 2°C. Significant rainfall (116 mm) and mostly overcast skies.

40 Poor

Comfort

Feels Like Cold
C
Temperature
91%
Humidity
Very Humid

Weather

116 mm
Rainfall
5.9 m/s
Wind
Light Breeze
0.0
UV Index
Low
7.1h daylight

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