What is the weather like in Phoenix vs San Diego in September?

In September, Phoenix averages 39°C high / 26°C low with about 12 mm of rain; San Diego averages 26°C high / 19°C low with about 6 mm.

Phoenix vs San Diego in September

San Diego is the better pick in September — 91 vs 49 on SeasonMap's comfort score. San Diego is warm, dry, muggy air, while Phoenix is sweltering, dry, clean air.

Phoenix vs San Diego — September climate, side by side

	Phoenix	San Diego
Comfort score	49/100 (F)	91/100 (S)
Feels-like high	38°C	27°C
Avg high / low	39° / 26°	26° / 19°
Rainfall	12 mm	6 mm
Rainy days	2	1
Humidity	33%	77%
Air quality (AQI)	45	53

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

Phoenix vs San Diego in September — FAQ

Is September better in Phoenix or San Diego?: San Diego is the better pick in September — 91 vs 49 on SeasonMap's comfort score. San Diego is warm, dry, muggy air, while Phoenix is sweltering, dry, clean air.
What is the weather like in Phoenix vs San Diego in September?: In September, Phoenix averages 39°C high / 26°C low with about 12 mm of rain; San Diego averages 26°C high / 19°C low with about 6 mm.