Winters in Clondalkin are chilly, with January temperatures averaging around 4°C and dropping as low as -8°C. The coldest months, December and January, see average highs of just above freezing, while February is slightly warmer. Spring arrives slowly, with March and April temperatures gradually rising to averages of 7°C, still quite cool for the time of year. Summer brings warmth, with June, July, and August averaging around 14-17°C, although there can be hot spells with temperatures reaching up to 24-29°C in these months. Autumn is mild, with September and October temperatures ranging from 5-20°C on average, before cooling off again in November and December.