Weather in Ireland in September

The weather in Ireland in September is still holding on to the tail end of summer, but hints of fall are already starting to slip through. Temperate temperatures, shorter daylight hours and a landscape where golden hues are just beginning to appear. It’s a perfect time for coastal drives along the Wild Atlantic Way or walking the leafy trails of Phoenix Park in Dublin. Crowds are thinning, so big hitters like the Cliffs of Moher or Giant’s Causeway feel a bit less hectic. Rain? It’s always a possibility — welcome to Ireland. Pop into a pub for a pint and some live trad music or browse independent bookstores in Galway’s Latin Quarter. Pack layers and a solid rain jacket, and you’ll be all set to enjoy Ireland’s mellow, early-autumn vibe.

Ireland in September at a glance

• Temperatures in Ireland in September range from 52°F to 60°F (11°C to 16°C) with occasional rain.
• Expect peak fall colors - golden forests and vibrant red leaves in places like Killarney National Park.
• Tourist crowds are fading, making it a perfect time to visit highlights without the hustle of summer.
• As the evenings grow darker, Ireland seems cozier than ever. Stop by a traditional pub for live music and a pint of beer.

Is September a good time to visit Ireland?

September is one of the best months to explore Ireland’s lush countryside before the full arrival of the fall. The weather in Ireland in September is mild and slightly unpredictable, with temperatures ranging from 52°F to 60°F (11°C to 16°C). You’ll get a mix of sunny days and the occasional rain shower — classic Irish weather — so packing layers and a rain jacket is smart.

The transition into fall means green fields are still vibrant, but you’ll see hints of gold and orange creeping into the trees. Coastal walks, like the Howth Cliff Path or along the Dingle Peninsula, are particularly striking under the soft September light. Plus, the summer crowds have mostly dispersed, making iconic sites more serene.

If you’re after a quieter time to visit, September strikes a perfect balance. Whether it’s exploring scenic trails, diving into local history, or enjoying a pint in a traditional pub, Ireland’s early fall charm won’t disappoint.

Rough Guides tip: read all about the best time to visit Ireland.

Average daily temperatures in September

In September, the average daily temperature in Ireland ranges from highs of 60°F (16°C) to lows of 52°F (11°C). The weather is mild but changeable, with a mix of sunny spells and passing rain showers — a classic for Ireland in early fall.

Regional differences are small but noteworthy:

• Eastern areas such as Dublin tend to be drier, with comfortable daytime temperatures and cool evenings, making them ideal for walking around the city.
• Western coastal areas such as Galway and County Kerry are a little cooler, with maximum temperatures around 59°F (15°C) and more rainfall, thanks to Atlantic winds.
• Northern areas experience cooler nights, with lows occasionally dipping to 48°F (9°C), especially in rural or elevated spots.
• Southern regions like Cork and Waterford are the warmest, with daytime highs reaching up to 63°F (17°C), ideal for exploring Ireland’s scenic coastline.

Snow isn’t on the cards, but the weather in Ireland in September can shift quickly. Bring layers, a waterproof jacket, and sturdy shoes to stay comfortable as you explore.

What about the crowd and cost?

September in Ireland marks the end of the busy summer season, so while the crowds have thinned out, the country still has a lively atmosphere. Popular spots are less packed, making it easier to enjoy the experience without elbowing through tourists. Smaller towns and scenic areas also feel more relaxed, but without the sleepy mood of the deep off-season.

In terms of cost, September falls in the “shoulder” season, so prices start to come down from the peak summer months. Accommodations and flights are often more affordable, though not as much as in late fall.

Looking for more options for your vacation in September? Find the perfect vacation destination with our top suggestions.

Things to do in Ireland in September

September in Ireland is a fantastic time to explore the country’s mix of vibrant cities, stunning landscapes, and cultural events. With mild weather and smaller crowds, you’ll have plenty of room to enjoy it all.

Explore the Wild Atlantic Way

Take advantage of the fading summer light and drive along Ireland’s famous Wild Atlantic Way. Stop at highlights like the Cliffs of Moher or Connemara, where the coastline begins to hint at autumn’s colors.

Walk in Killarney National Park

September is perfect for exploring Killarney National Park. Wander through lush woodlands, take a boat trip on Lough Leane or visit Ross Castle - with fewer tourists, you can be virtually alone in this magical place.

Enjoy Dublin’s cultural scene

Dublin is lively in September, with events like the Dublin Fringe Festival in full swing. Visit iconic spots like Trinity College or enjoy a pint in a traditional pub while soaking up the city’s vibrant atmosphere.

Traveling to Dublin? Don't miss the opportunity to choose the best places to stay in the city.

Attend a harvest festival

Celebrate Ireland's agricultural roots at harvest festivals such as the Waterford Harvest Festival. These events feature food markets, live music and cooking workshops - the perfect way to sample local flavors and meet friendly locals.

Go whale watching

Head to West Cork or County Kerry for whale watching in September, when migrating humpback and fin whales begin to appear off the coast. Bring binoculars to be able to see these magnificent creatures up close.

Festivals and events in Ireland in September

September in Ireland is a combination of cultural celebrations, food festivals and lively events, making it a great time to visit. Here are some highlights:

• Dublin Fringe Festival: A showcase of cutting-edge theater, comedy, and live performances across the city. Perfect for lovers of the arts, but book tickets early —popular shows sell out fast.
• Waterford Harvest Festival: Celebrate Irish food and farming at this delicious event featuring local produce markets, cooking demos, and family-friendly entertainment. It’s a feast for your taste buds.
• Clifden Arts Festival (County Galway): This small-town festival brings great energy: poetry readings, traditional music and art exhibitions in the heart of Connemara.
• Lisdoonvarna Matchmaking Festival (County Clare): A quirky, month-long tradition where singles gather for music, dancing, and, of course, matchmaking. Great for experiencing authentic Irish craic.

From artistic showcases to culinary delights, September’s festivals offer something for everyone. Be sure to book accommodation and tickets in advance if you’re visiting during a major event.

Plan your trip with our Ireland itineraries

Our Ireland itineraries are crafted to help you experience the best of the country, stress-free. Think of them as a starting point — perfect for planning, but flexible enough to adjust to your own pace and interests. After all, travel is about freedom, but a little planning goes a long way.

• Ireland Itinerary 7 days: Spend a week exploring highlights like Dublin’s historic landmarks, the Cliffs of Moher, and the scenic Ring of Kerry. This itinerary is ideal for a quick dive into Ireland’s cities and natural beauty.
• Ireland Itinerary 10 days: With 10 days, you can cover Dublin, Galway, and Cork, plus add stops like the Dingle Peninsula or the Giant’s Causeway in Northern Ireland for a more in-depth adventure.
• Ireland and Scotland Itinerary: Split your time between Ireland’s rugged west coast and Scotland’s historic cities like Edinburgh and Glasgow, with bonus visits to castles and lochs in the Highlands.