Ireland's weather in September is cool to mild, with the month marking the end of summer. If you want to visit in September, we suggest Dublin, Killarney National Park, the Cliffs of Moher and Limerick. Read on to find out more about travel and weather in Ireland, including temperatures, rainfall, humidity, and tips for September.
Ireland Weather in September: Overview
Averages:
- Temperature range: 10–17°C (50–63°F)
- Rainfall: 9 cm (3 inches)
- Rainy days: 14
- Sunshine hours/day: 5
- Humidity: around 73% (damp and humid throughout the country)
September is the beginning of fall in Ireland, with temperatures dropping slightly when compared to July and August — around 10–17°C (50–63°F). The daytime sunshine adds up to approximately 5 hours a day throughout the month of September.
In terms of humidity levels, Ireland is quite damp and humid in September, throughout all of the country. This is because there are around 14 rainy days throughout the month, with rainfall averaging a moderate 9 cm (or 3 inches). Visitors in September should bring an umbrella or a waterproof layer, just in case.
September Climate Comparison (Averages) for Ireland's Top Tourism Areas
| City/Area | Temperatures | Rainfall |
|---|---|---|
| Dublin (main city, Irish culture, bars, Guiness) | Cool to Mild | Low |
| Galway (harbor city, history, architecture) | Cool to Mild | Moderate |
| Cork (foodie capital, architecture, history) | Cool to Mild | Moderate |
| Limerick (culture, old buildings, museums) | Cool to Mild | Moderate |
| Killarney (national park scenery, hikes, castle, abbey) | Cold to Mild | Moderate |
| City/Area | High (ºC) | Low (ºC) |
|---|---|---|
| Dublin (main city, Irish culture, bars, Guiness) | 17°C (63°F) | 10°C (50°F) |
| Galway (harbor city, history, architecture) | 17°C (63°F) | 10°C (50°F) |
| Cork (foodie capital, architecture, history) | 17°C (63°F) | 10°C (50°F) |
| Limerick (culture, old buildings, museums) | 18°C (64°F) | 11°C (52°F) |
| Killarney (national park scenery, hikes, castle, abbey) | 16°C (61°F) | 10°C (50°F) |
| City/Area | Rain (cm) | Rain (in) |
|---|---|---|
| Dublin (main city, Irish culture, bars, Guiness) | 6 | 2 |
| Galway (harbor city, history, architecture) | 9 | 4 |
| Cork (foodie capital, architecture, history) | 9 | 4 |
| Limerick (culture, old buildings, museums) | 8 | 3 |
| Killarney (national park scenery, hikes, castle, abbey) | 12 | 5 |
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The Best Places to Visit in Ireland in September
Given that temperatures still range between cool and mild in Ireland in September, we would recommend spending some time both in the outdoors and the indoors. This is especially a good idea in case you have a rainy day or two.
We would recommend spending some time in Dublin, Killarney National Park, the Cliffs of Moher and Limerick.
If you are finding it difficult to plan your trip, our experts can always help you put together your ideal Ireland itinerary. Just let us know where you want to go, how long you're planning to stay, and what you want to see, and we can arrange everything from entrance tickets to transport to accommodation. Contact us to start planning your Ireland trip.
1. Take a Day Trip from Dublin to Glendalough Valley
Dublin is likely your first stop in Ireland, and you should definitely spend some time walking around the city, seeing its museums, and taking in the sights. You can find a little more about what to see in Ireland in our pieces about visiting Ireland in May and June.
After you've seen Dublin, we would also recommend a day trip to Glendalough Valley, in Wicklow Mountains National Park. The valley is found between two lakes, and the spectacular scenery is unique, drawing visitors from all over the world.
There is Monastic City there too, one of the most important monastic sites in Ireland. It was founded in the 6th century, and up to this day you can see remains including the Round Tower and the large granite cross behind the Priest's House.
This site is a must visit for any budding archaeologist, or those looking to learn more about Irish history.
2. Hike Killarney National Park
Killarney National Park is a must-see on any visit to Ireland, regardless of the weather. Although we do recommend bringing some waterproof gear or an umbrella when visiting in September, the park is still well worth going to.
There are plenty of hiking routes there. If you want to go for a walk in flatter territory, for which there are plenty of trails, including the 1–2-hour long Ross Castle Loop, which includes a visit to Ross Castle and a river walk.
For those wanting a challenge, we recommend the Torc Mountain path which takes around 4 and a half hours. The path takes you up some steep steps and takes in beautiful sights as a result, including waterfalls, an old farm dwelling, and panoramic views of Muckross Lake.
3. Breathe in the Fresh Sea Air at the Cliffs of Moher
You'll likely have seen pictures of the Cliffs of Moher if you have done some research into visiting Ireland, given that they are one of the best-known sights in the country. For anyone visiting in September, we highly recommend checking out the Cliffs.
There will be fewer crowds there in September when compared to July and August, but it does still get busy due to its year-round popularity.
An information center on site can help you plan your route, since there are some safe trails nearby for a walk. Alternatively, just look out over the rugged Atlantic Ocean and breathe in the fresh sea air. Visiting at sunset will give you some of the best views.
4. Stretch Your Legs on a Walking Tour Around Limerick
Just further south beyond the Cliffs of Moher, you will find Limerick, the third biggest city in the Republic of Ireland and the fourth biggest city on the entire island of Ireland. The city was founded by Scandinavian settlers in the Viking Age (793–1066), and has some interesting history as a result.
We recommend getting a tour guide for the day, as then you can explore all that the city has to offer. Global Highlights can help you arrange this if needed.
There is the Hunt Museum to visit, which you can read more about in our piece about visiting Ireland in January, as well as King John's Castle, and Saint Mary's Cathedral. The Milk Market is also a fun flea market to enjoy a little bit of day-to-day life in Limerick, and you might even find some things to take back home.
End of High Season: More Expensive and More Crowds
September is the end of the high season, and if you visit in the latter part of the month, you will definitely have missed peak travel time.
Visiting earlier in the month you might find that prices are slightly higher for accommodation and travel, since there are still some European countries with school holidays and because the weather is still mild during this time of the year.
What to Wear in September
For visitors in September, we would recommend bringing some additional layers to put on in case the temperature drops. This is particularly true if you are visiting towards the end of the month, when autumn weather sets in throughout Ireland.
We do also suggest bringing an umbrella or a waterproof jacket, as there is a chance of rain in Ireland in September, particularly if you are visiting Killarney National Park, or Galway and Cork. Bringing waterproof shoes will also help ensure that your feet stay dry, particularly if you are planning on going for some hikes.
