September in Rome tends to be sunny with warm afternoons and evenings and comfortable to cool nights.
About 7-8 afternoons, mostly early in the month, will be humid.
Daytime high temperatures early in September tend to be near 27-28 C (81-83 F) but cool to 25-26 C (77-79 F) towards the end of this month.
A few of the warmer afternoons, especially early in the month, can reach up near 31 C (88 F).
The record high temperature in Rome during September is 38.4 (101.1 F).
Late night and early morning low temperatures will tend to be near 17 C (62-63 F) early in the month, cooling to 14-15 C (57-59 F) near the end of this month.
A few of the cooler mornings, especially late in September, can dip down near 10 C (50 F).
The record low temperature in Rome during September is 4.3 °C (39.7 F).
Sun and Rain
Rome during September normally sees about 18 sunny days, 3 partly sunny, and 9 cloudy days.
A cloudy day is more likely to occur near the end of the month than at the beginning.
About 6-7 days normally record some rain, 4-5 days record at least 1 mm (0.04 inches) and about 2 days will record rainfalls of at least 10 mm (0.4 inches).
The number of daylight hours decreases rapidly this month from about 13.1 hours on the 1st to 11.8 hours by the 30th.
The wind speeds during this month are mostly light to gentle averaging 6-19 kph (4-12 mph), however, can briefly be moderate at 20-28 kph (13-18 mph).
Ocean and Beaches
Within about an hour of the city are several good beaches and the water remains warm this month, averaging 23-24 C (73-76 F).
What to Wear in Rome During September?
September in Rome offers mostly warm days and evenings. It is best to dress light and airy.
Cotton pants, summer dresses, shorts, tees, or other cotton tops work well.
Late nights and early mornings can be a bit cool, so consider a windbreaker and sweater as well.
A travel umbrella or light rain jacket will come in handy for the few rainy days.
Also, bring sandals and comfortable walking shoes. If you plan to visit the Vatican, best to check their dress code first.
Things to Do in Rome in September
There should be plenty of sunny days to enjoy this month, making it an excellent time to consider taking a pay-what-you-wish walking tour in Rome.
If you plan on visiting early in September, you might want to take advantage of Io Vado al Museo, a program which allows you to visit some of the most notable sites in the city for free on the first Sunday of the month.
September is also the month of the Roma Europa Festival, which means there will be plenty of interesting theatrical performances to see.
For even more ideas, make sure to read our full post covering things to do in Rome in September.