Portmarnock weather in September (Dublin County, Ireland)

Wondering what the weather is like in Portmarnock during September? Use this page to get an overview of the month’s weather conditions.

Temperatures

In September, Portmarnock typically experiences moderate temperatures and moderate rainfall. The summer season is characteristic of September. Throughout the daytime, temperatures often hover around 17°C. However, as the sun sets and evening approaches, there's a noticeable cool-down. Temperatures gently drop to a more temperate 12°C.

Precipitation

Portmarnock in September usually receives moderate rainfall, averaging around 78 mm for the month. Historically, approximately 15 days this month are expected to have rain.

Average sunshine

The area experiences a moderate amount of sunshine, with approximately 128 hours of sunlight expected. This makes it neither too gloomy nor overly bright.

If your ideal day consists of dry skies and moderate temperatures July and August generally stand out with the best circumstances. While January, February and December tend to showcase less optimal conditions.

For an in-depth look at the yearly conditions, visit our specialized Portmarnock climate page with graphs.

 

Portmarnock, monthly averages in September

Min Temperature 12°C  

Max Temperature 17°C  

Water Temperature 15°C *  

Chance of Rain 50%  

Precipitation 78 mm  

Rainy days 15 days  

Humidity 71% *  

Windspeed 14 km/h *  

Sunshine 128 hours *  

Percentage Sunshine 33% *  

* Data from: Dublin, Ireland (7 KM, 4 Miles).

Where to go in Ireland in September

Find out more about the weather in Ireland and which places have the best travel conditions in this month.

Weather conditions Weather

Temperatures

Precipitation

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Legend perfect weather pleasant tolerable unpleasant poor

Perfect weather is subjective. On this map perfect weather has been defined with temperatures between 20°C and 29°C and not too much precipitation (less than 90 mm a month).

So, what should you wear in this month?

For visitors traveling to Portmarnock, we recommend wearing layers. So maybe a skirt, t-shirt, shorts for during the day and jeans and a warm jacket for some days and evenings. Bring a rain jacket in case it rains during your stay. Plan on layering your clothes. With a water temperature of around 15°C there is no need to bring your swimwear.

What To Do

We rated the following activities from 1 (least suitable) to 10 (best) to do.

Swimming

6/10

Cycling

6/10

Walking

6/10

Camping

8/10

Outdoor sports

9/10

Interested in more climate information?

This site provides you with all the information you need about the climate in Portmarnock.

Our site offers climate and forecast data for every country in the world. Are you going to Ireland? On this website you can find historical weather averages for many cities in Ireland. Not sure yet where to go? We now have a tool which recommends destinations that suit your ideal travel conditions. Find out where to go with our weather planner.