In September, Nagaoka typically sees daytime highs of 26.0°C and overnight lows around 16.8°C. Compared to the annual average high of 17.7°C, September runs +8.3°C.
September in Nagaoka averages a daytime high of 26.0°C and an overnight low of 16.8°C.
September runs +8.3°C compared to Nagaoka's annual average high of 17.7°C, ranking #3 of 12 months by warmth.
Plan for daytime highs near 26.0°C and cooler evenings around 16.8°C.