Weather in Rijeka in September 2025
Average weather
Average temperature in Rijeka in September
The expected average maximum temperature in September is +26°C with a maximum of +30°C and a minimum of +15°C.
The average maximum temperature goes up 7% by the end of the month, compared with the beginning of the month, from +26°C to +27°C.
Is Rijeka warm or cold in September?
Rijeka is typically warm in September.
Maximum temperatures go down compared to the previous month from +29°C to +24°C. The minimum temperature also goes down from +20°C to +16°C.
It’s generally warm, but pack a long-sleeve shirt for evenings.
Take a look at how September is compared to other months in Rijeka:
Water temperature in Rijeka in September
Water in Rijeka in September is Comfortable. It varies from +20°C to +26°C, with an average of +23°C. This is almost similar to the air temperature, which averages +24°C.
The water temperature in September is one of the warmest of the entire year:
Can you swim in Rijeka in September?
Climate in Rijeka in September
| August | September | October | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +29°C | +24°C | +19°C | ||||
| Min. temperature | ||||||
| +11°C | +9°C | +2°C | ||||
| Max. temperature | ||||||
| +39°C | +33°C | +28°C | ||||
| Rainfall | ||||||
| 131 mm | 221 mm | 261 mm | ||||
| Wind | ||||||
| 1 m/s | 2 m/s | 2 m/s | ||||
| Avg. water temperature | ||||||
| +24°C | +23°C | +19°C | ||||
| Humidity | ||||||
| 60% | 67% | 72% | ||||
| Air pressure | ||||||
| 1013 HPa | 1015 HPa | 1017 HPa | ||||
| Sunny days | ||||||
| 13 | 11 | 10 | ||||
| Cloudy days | ||||||
| 3 | 5 | 5 | ||||
| Rainy days | ||||||
| 10 | 11 | 14 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
September weather is still as good as in August. It’s getting colder in September. From +29°C in the day, the average maximum temperature lowers to +24°C. Prepare for more rain. Average rainfall goes from 131 mm to 221 mm. Humidity rises from 60% to 67%. Winds are stronger in comparison to August, going up from 1 m/s to 2 m/s on average. The days becoming less sunny, going from 13 sunny days in August to 11 in September.
October brings much the same weather, it remains good.
Wind
The average wind speed is 3 m/s getting up to 5 m/s which is a light breeze; barely moving the tree leaves.
The average wind speed in Rijeka is gradually increasing during September, going from 1 m/s to 1 m/s over the course of the month.
Rain
How was the weather last September in Rijeka?
Climate Change over Years
The climate in Rijeka in September has not changed much over the last 43 years.
The average temperature was the lowest in 1980 (+16°C) and the highest in 2011 (+20°C). The driest year was 2003 with only 1149 mm of rainfall, and the wettest year was 2019 with 4603 mm.
FAQ
Is September a good time to visit Rijeka?
Can you sunbathe in Rijeka in September?
Can you swim in Rijeka in September?
Is Rijeka rainy in September?
Is it sunny in Rijeka in September?
Other cities in Croatia
Monthly weather in Rijeka
Source of the data
For this page, we’ve looked at the typical weather in Rijeka, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.