Click on a day for an hourly weather forecast
The temperatures in Portrush in September are quite cold with temperatures between 9°C and 15°C, warm clothes are a must.
You can expect about 3 to 8 days of rain in Portrush during the month of September. It’s a good idea to bring along your umbrella so that you don’t get caught in poor weather.
Our weather forecast can give you a great sense of what weather to expect in Portrush in September 2025.
If you’re planning to visit Portrush in the near future, we highly recommend that you review the 14 day weather forecast for Portrush before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 6° / 2° | 11 | 14 | 6 | 98 mm | Awful | Portrush in January |
| February | 7° / 2° | 10 | 11 | 7 | 105 mm | Awful | Portrush in February |
| March | 9° / 3° | 10 | 17 | 4 | 89 mm | Awful | Portrush in March |
| April | 11° / 4° | 7 | 21 | 2 | 77 mm | Awful | Portrush in April |
| May | 13° / 7° | 9 | 22 | 0 | 95 mm | Bad | Portrush in May |
| June | 16° / 9° | 8 | 22 | 0 | 117 mm | Ok | Portrush in June |
| July | 17° / 11° | 9 | 22 | 0 | 131 mm | Ok | Portrush in July |
| August | 17° / 11° | 10 | 21 | 0 | 129 mm | Ok | Portrush in August |
| September | 15° / 9° | 7 | 23 | 0 | 85 mm | Ok | Portrush in September |
| October | 12° / 7° | 10 | 21 | 0 | 118 mm | Bad | Portrush in October |
| November | 9° / 5° | 10 | 19 | 1 | 112 mm | Bad | Portrush in November |
| December | 6° / 3° | 10 | 17 | 3 | 97 mm | Awful | Portrush in December |