Weather in Londonderry in September
How warm is it in Londonderry in September?
In September the typical daytime high in Londonderry is 16.0 °C on average, from 17.1 °C at the start to 14.8 °C at the end of the month.
That is 1.5 °C cooler than in August and 2.7 °C warmer than in October.
The last 10 years were 0.6 °C warmer than more than 40 years ago.
Click a day for more: afternoon and night, the usual range, records and how fast it is warming.
The average of the weather stations Malin Head (42 km), Armagh (84 km) and Connaught (155 km); nearer ones count more.