Paris is set for another sharp May turn. Forecasts for the week of May 18 called for showers at the start, then a steady warm-up that could push the city toward 28 to 29 C by the end of the week.
The change matters because it fits a pattern Parisians know well: a cool, wet spell can give way quickly to near-summer heat. Paris often sits in the middle of a tug-of-war between cold air coming down from the north and warm air pushing up from the south, and the result can change in a matter of days. At the Paris-Montsouris station, the 1991-2020 normal average May temperature was 15.6 C, with average highs of 20.2 C and lows of 11.1 C. The city also sees about 69 mm of precipitation on average in May and more than 9 days of rain of at least 1 mm.
That backdrop helps explain why a week that begins with showers and ends near 29 C is not unusual, even if the swing is dramatic. Atlantic disturbances reaching Île-de-France bring clouds, rain and a chill. When high pressure returns, the sky can clear fast and temperatures can rise just as quickly. Spring adds another wrinkle: cold pockets of air aloft can destabilize the atmosphere and favor showers and thunderstorms in Paris.
The recent record shows how erratic the season has been. Météo-France described May 2024 as remarkably rainy and short on sunshine. It said that month brought more than 15 days of rain across much of France and was the wettest May in the country since 2013. By contrast, spring 2025 was unusually hot, sunny and dry across the northern half of France, and it ranked third among the warmest springs since 1900. That season also included heat spikes at the end of April into early May and again at the end of May.
The shift from one spring to the next is part of a broader trend. France is warming, and Paris weather is showing it through more abrupt swings between damp, cool periods and bursts of early heat. For the week of May 18, the city was forecast to experience both in the same stretch, with showers first and a fast rise toward 28 to 29 C before the week is out.
