In September, Rijeka typically sees daytime highs of 21.9°C and overnight lows around 11.2°C. Compared to the annual average high of 16.0°C, September runs +6.0°C.
September in Rijeka averages a daytime high of 21.9°C and an overnight low of 11.2°C.
September runs +6.0°C compared to Rijeka's annual average high of 16.0°C, ranking #4 of 12 months by warmth.
Plan for daytime highs near 21.9°C and cooler evenings around 11.2°C.