Montrouge experiences a mild and relatively stable climate, with temperatures gradually warming up as the year progresses. Winters are chilly, with January and February averaging around 4-6°C, while springs bring moderate temperatures, slowly increasing to an average of 12°C in May. Summers are warm but not hot, with July and August averaging around 19°C, followed by a gentle decline into autumn. As the seasons shift again, temperatures drop, returning to winter-like conditions by November and December, averaging around 6°C. The overall trend is one of mild temperature fluctuations, with no extreme highs or lows throughout the year.