Monthly climate guide
Rijeka weather in September
Expect mild weather in Rijeka in September: afternoons reach about 20°C (68°F), while nights drop to around 10°C (50°F). Around 138 mm of rain falls over the month (wet), and skies are often cloudy. Daytime highs are 5°C cooler than August and 5°C warmer than October.
What stands out in September
- Temperatures are falling — expect highs around 5°C lower by October.
- In Rijeka, September is early autumn.
- Rijeka is usually about 3°C cooler than Krk, 30 km away, in September.
Avg high
20°C
68°F
Avg low
10°C
50°F
Rainfall
138 mm
wet
Humidity
79%
relative
Sky
58%
cloud · often cloudy
Rijeka weather by month
Show the monthly averages as a table
| Month | Avg high | Avg low | Rain | Humidity | Cloud cover |
|---|---|---|---|---|---|
| January | 3°C / 38°F | -3°C / 27°F | 80 mm | 91% | 74% |
| February | 4°C / 39°F | -3°C / 26°F | 112 mm | 90% | 75% |
| March | 9°C / 49°F | 0°C / 32°F | 81 mm | 84% | 63% |
| April | 15°C / 58°F | 4°C / 39°F | 76 mm | 78% | 64% |
| May | 18°C / 64°F | 8°C / 46°F | 122 mm | 78% | 66% |
| June | 22°C / 72°F | 12°C / 54°F | 92 mm | 76% | 56% |
| July | 24°C / 76°F | 14°C / 58°F | 77 mm | 74% | 49% |
| August | 25°C / 77°F | 14°C / 57°F | 80 mm | 73% | 43% |
| September | 20°C / 68°F | 10°C / 50°F | 138 mm | 79% | 58% |
| October | 15°C / 59°F | 6°C / 43°F | 140 mm | 85% | 65% |
| November | 9°C / 49°F | 3°C / 37°F | 155 mm | 91% | 75% |
| December | 5°C / 41°F | -2°C / 29°F | 101 mm | 92% | 70% |
What to pack for September
- T-shirts plus a light layer for the evening
- Comfortable trainers or sandals for long walks
- A compact umbrella or packable rain jacket
- Water-resistant shoes
Is September a good time to visit Rijeka?
Compare the months in the chart above to find your ideal window.
Best time to visit Rijeka →Other Croatia cities in September
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Rijeka weather in September. WeatherCompare, 2026 (NASA POWER / ERA5, 2011–2020 monthly averages). https://weathercompare.eu/weather/croatia/rijeka/september
<a href="https://weathercompare.eu/weather/croatia/rijeka/september">Rijeka weather in September</a> (WeatherCompare)
<iframe src="https://weathercompare.eu/embed/croatia/rijeka" width="300" height="160" style="border:0;border-radius:12px" loading="lazy" title="Rijeka weather in September"></iframe> <p style="font-size:12px"><a href="https://weathercompare.eu/weather/croatia/rijeka/september">Rijeka weather in September</a> – WeatherCompare</p>
Rijeka in September: quick answers
Is September a good time to visit Rijeka?
September is one of the wetter months in Rijeka, with about 138 mm of rain. You can still go: pack a rain jacket and keep plans flexible.
How warm is Rijeka in September?
Average highs are about 20°C (68°F) and average lows about 10°C (50°F), based on 10 years of daily data.
Does it rain a lot in Rijeka in September?
Rijeka typically gets around 138 mm of rain in September — wet.
Figures are long-term averages for the area around Rijeka (NASA POWER / ERA5, 2011–2020), not a forecast for a specific year. For upcoming days, see the live multi-source forecast.