What is the weather like in Belfast vs London in September?

In September, Belfast averages 18°C high / 11°C low with about 80 mm of rain; London averages 21°C high / 12°C low with about 56 mm.

Belfast vs London in September

London is the better pick in September — 84 vs 79 on SeasonMap's comfort score. London is nice, a little rain, clean air, while Belfast is cool, rainy, clean air.

Belfast vs London — September climate, side by side

	Belfast	London
Comfort score	79/100 (B)	84/100 (A)
Feels-like high	15°C	19°C
Avg high / low	18° / 11°	21° / 12°
Rainfall	80 mm	56 mm
Rainy days	13	11
Humidity	82%	78%
Air quality (AQI)	35	46

Monthly climate normals (ERA5 reanalysis). Comfort scores are SeasonMap estimates.

Belfast vs London in September — FAQ

Is September better in Belfast or London?: London is the better pick in September — 84 vs 79 on SeasonMap's comfort score. London is nice, a little rain, clean air, while Belfast is cool, rainy, clean air.
What is the weather like in Belfast vs London in September?: In September, Belfast averages 18°C high / 11°C low with about 80 mm of rain; London averages 21°C high / 12°C low with about 56 mm.