ClimateAverages

Castlereagh Weather in September

JanFebMarAprMayJunJulAugSepOctNovDec
September daytime high
15.8°C
September overnight low
9.9°C
September average
12.9°C

In September, Castlereagh typically sees daytime highs of 15.8°C and overnight lows around 9.9°C. Compared to the annual average high of 12.0°C, September runs +3.8°C.

vs. annual avg high
+3.8°C
Rank among 12 months
#4 warmest
Hottest year overall
2025

Where September ranks in Castlereagh

JanFebMarAprMayJunJulAugSep16°OctNovDec

FAQ

What is the average temperature in Castlereagh in September?

September in Castlereagh averages a daytime high of 15.8°C and an overnight low of 9.9°C.

Is September warm or cold in Castlereagh?

September runs +3.8°C compared to Castlereagh's annual average high of 12.0°C, ranking #4 of 12 months by warmth.

What should I pack for Castlereagh in September?

Plan for daytime highs near 15.8°C and cooler evenings around 9.9°C.

Other months for Castlereagh

JanuaryFebruaryMarchAprilMayJuneJulyAugustOctoberNovemberDecember

September in nearby cities

BelfastDerryLisburnNewtownabbeyBangorCraigavon