In September, Lahti typically sees daytime highs of 13.8°C and overnight lows around 5.0°C. Compared to the annual average high of 7.8°C, September runs +6.0°C.
September in Lahti averages a daytime high of 13.8°C and an overnight low of 5.0°C.
September runs +6.0°C compared to Lahti's annual average high of 7.8°C, ranking #5 of 12 months by warmth.
Plan for daytime highs near 13.8°C and cooler evenings around 5.0°C.