Is the weather good in Ireland in September 2025?
For the past few decades, the average daily temperatures in Ireland during September have been around +63°F.
In Ireland the temperature rarely varies more than seven degrees between the different parts with the highest temperature +63°F in Shannon to +61°F in Cork. So you should be able to pack for similar conditions wherever you go in the country.
Temperature, wind and humidity in September
- rainiest? Shannon, with an average of 3 mm of rain and humidity of 85%;
- warmest? Shannon, with daytime temperatures averaging +63°F;
- windiest? Dublin, with an average of 4 m/s;
- coolest? Cork, with daytime temperatures averaging +61°F;
How good is the weather in Ireland in September?
How warm is it in Ireland during September?
This is how hot it usually is in September
- Average maximum temperature for the month: +63°F;
- Average minimum temperature for the month: +52°F;
- Highest monthly temperature: +64°F;
- Lowest monthly temperature: +50°F;
Monthly temperatures:
- Warmest: July with an average +66°F during the day;
- Coldest: January with an average +46°F of the day;
- Hottest month in hottest city: July in Dublin;
- Coldest month in coolest city: January in Cork;
Winds in Ireland during September
September tends to offer light winds averaging 3 m/s. However, coastal cities may experience breezes during the mornings and afternoons.
Comparison between cities in September:
- Highest average wind speed: Dublin with 5 m/s;
- Lowest average wind speed: Cork with 3 m/s;
- Windiest day of the month: Dublin with 5 m/s;
- The least windy day of the month: Cork with 2 m/s;
Humidity and precipitation in Ireland in September
Comparison between cities in September:
- Highest average rainfall: Shannon with 80 mm;
- Lowest average rainfall: Cork with 70 mm;
- Most number of rainy days: Shannon with 19 rainy days;
- Least number of rainy days: Cork with 17 rainy days;
- Highest risk of rain during the day: Shannon with 63%;
- Least risk of rain during the day: Cork with 57%;
- Highest average humidity: Cork with 86%;
- Lowest average humidity: Dublin with 81%;
Tips for traveling to Ireland in September
Looking for some tips for traveling to the sun, snow, or whatever you're aiming for Ireland? Activities, weather, and clothing are closely linked. In addition, it's important to pack only what you really need so you don't have to worry about heavy packing or paying extra baggage fees.
Here is some advice on what to pack and what kind of activities you can do in the Ireland based on the weather that September is expected to bring. The advice applies to the country as a whole – local weather and possible activities may differ somewhat.
Pack right for September
- For light showers, an umbrella or a thin and light rain cape is usually sufficient, while more rain may require rainwear and rain boots.
- Cool weather is between warm and cold. This means you can bring long pants and/or a longer skirt and an extra sweater. Be aware that cool days can alternate with cold nights - it may be wise to also pack a hat, gloves and a scarf.
- Light winds are probably most comfortable in hot weather but is cooling in cool and cold weather. If it is hot (when the air temperature is about 30 degrees), the wind can have a warming effect. A thin, windproof jacket and long trousers help to counteract these effects.
- High humidity means that the air conducts heat to and from the skin more easily. For example, if the air is hot (above skin temperature), it will be harder to stay cool. On the other hand, if the air is cool or cold, it is more difficult to stay warm. In high humidity, the choice of clothing makes less of a difference. However, your physical activity plays a bigger role.
FAQ
What can you do outside when it's warm in Ireland?
Is September a good time to visit Ireland?
Monthly weather in Ireland
Source of the data
For this page, we’ve looked at the typical weather in Ireland, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.