Castlereagh Weather in September

September in Castlereagh sees daytime temperatures around 17°C (63°F) and lows of 11°C (52°F) at night. With around 85 mm (3.3 in) of rainfall expected, it's worth packing a rain jacket.

Rainfall in Castlereagh in September

Looking at the last 30 years, the data shows about 17 days with rain, averaging 85 mm (3.3 in) for the month. Neither particularly heavy nor particularly frequent, the rain this month is about average. A light jacket should be enough on most wet days.

Temperature in Castlereagh in September

September in Castlereagh sees highs of 17°C (63°F) and lows of 11°C (52°F) overnight. September is a notable month of the summer season. Conditions are often most pleasant around the middle of the day. At 11°C (52°F) overnight, it can feel quite a bit cooler after dark. Worth packing something warmer for evenings, but the cooler temperatures are ideal for sleeping.

Sunshine in Castlereagh in September

The city usually sees around 109 hours of sunlight, indicating a moderately sunny period.

Wind Speed in Castlereagh in September

Wind speeds average 4 m/s (8 knots) during September. At this speed, expect moderate winds that can raise dust and move small branches. Since this is an average, some days have gentle light winds while others experience stronger breezes that are quite noticeable.

Average water temperature in September

At 13°C (55°F), the water is cool but manageable for those who don't mind a bit of a shock getting in. Most people adjust after a few minutes.

If you prefer enjoying temperate temperatures and rain-free days, July and August typically offer the best circumstances. If you're seeking pleasant, dry and sunny weather somewhere else in the world, our weather planner can help you explore other options.

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For a detailed overview over the year and the best time to visit the United Kingdom, check out our Castlereagh's climate page.

Castlereagh Temperature in September

Min Temperature 11°C (52°F)  

Max Temperature 17°C (63°F)  

Water Temperature 13°C (55°F) *  

Chance of Rain 56%  

Precipitation 85 mm (3.3 in)  

Rainy days 17 days  

Humidity 91% *  

Windspeed 4 m/s (8 knots) *  

Sunshine 109 hours *  

Percentage Sunshine 28% *  

* Data from: Belfast, Ireland (24 KM, 15 Miles).

What to Wear in Castlereagh in September

Pleasant temperatures in September mean you can pack light but flexibel pieces. Think cotton t-shirts, comfortable walking shorts, and one warmer layer for evenings. A light sweater or denim jacket works well. Prepare for significant rainfall with proper waterproof clothing and shoes. With water temperatures around 13°C (55°F), the water is quite cold for swimming. You can skip the swimwear unless you're particularly tough. Bring sunglasses since you'll have some sunny periods throughout the month

What To Do in Castlereagh in September

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

Swimming

5/10

Cycling

6/10

Walking

6/10

Camping

8/10

Outdoor sports

9/10

Select a Month

Check the conditions for any month of the year.

• January
• February
• March
• April

• May
• June
• July
• August

• September
• October
• November
• December

For a detailed overview over the year and the best time to visit the United Kingdom, check out our Castlereagh's climate page.

More climate data for Castlereagh

Temperature Rainfall Sunshine Humidity Wind Speed Water Temp

See the full Castlereagh climate overview or explore weather in the United Kingdom.