Rijeka weather in September 2026

Q: How hot is it in Rijeka in September?

Daytime temperatures usually reach 25°C in Rijeka in September with low heat and humidity, falling to 14°C at night.

Q: How sunny is it in Rijeka in September?

There are normally 8 hours of bright sunshine each day in Rijeka in September - that's 62% of daylight hours.

Q: How warm is the sea around Rijeka in September?

The average sea temperature around Rijeka in September is 22°C.

Q: Does it rain in Rijeka in September?

There are usually 10 days with some rain in Rijeka in September and the average monthly rainfall is 75mm.

Expect daytime maximum temperatures of 20°C in Rijeka, Croatia in September based on long-term weather averages. There are 7 hours of sunshine per day on average with 13 days with some rainfall and typically 143 mm of rainfall in the month.

20
20°C max day temperature
7
7 hours of sunshine per day
13
13 days with some rainfall
9
9°C min night temperature
13
13 hours of daylight per day
0
No heat & humidity
143
143 mm of monthly rainfall
5
5 (Moderate) UV index
21
21°C sea temperature

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The September weather guide for Croatia (Rijeka) shows long term weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Find out more about our data sources.

Metric (°C / mm) | Imperial (°F / inches)