Will I be cold?
Will I be cold in Rome in September?
Verdict
No — No, comfortable.
Lows stay near 62°F — you won't be reaching for the puffer.
Day vs. night
Day
81°F
Warm
Breathable fabrics; sunscreen matters more than a jacket.
Night
62°F
Comfortable
Comfortable outside without an extra layer.
Why
Rome in September averages highs of 81°F, lows of 62°F, 5 rainy days.
You can pack for the daytime temps and not worry about the evening dip.