The temperatures in Portoroz in September are comfortable with low of 15°C and and high up to 24°C.
You can expect rain for roughly half of the month of September in Portoroz. We’re expecting roughly 8 to 15 days of rain, so your rubber boots and umbrella are going to see plenty of use this month if you’re keen on staying dry.
Our weather forecast can give you a great sense of what weather to expect in Portoroz in September 2025.
If you’re planning to visit Portoroz in the near future, we highly recommend that you review the 14 day weather forecast for Portoroz before you arrive.
Temperatures
24° / 15°
Rainy Days
9
Snowy Days
0
Dry Days
21
Rainfall
240
mm
Sun Hours
11.0
Hrs
