Nagaoka experiences a temperate climate with distinct seasonal changes. Winters are chilly, with temperatures ranging from around 0°C in the colder months of January and December, to slightly warmer temperatures in February and March. As spring approaches, temperatures gradually rise, with April and May marking a significant increase in warmth, with average highs often reaching into the mid-twenties. Summer is hot and humid, with July and August being the warmest months, while September brings a welcome cool-down as autumn sets in. Autumn itself sees a return to milder temperatures, similar to those of spring, before the cycle begins anew.