Hot weather is expected this Thursday, May 28, and Friday, May 29, 2026, potentially disrupting the operation of some trains in Île-de-France. That’s the warning from Transilien SNCF on its website.
Until now under a yellow heatwave alert, Paris moves to an alerte orange starting this Thursday, May 28 at 12:00. Three other Île-de-France departments — the Hauts-de-Seine, Seine-Saint-Denis and Val-de-Marne — are also placed under orange heatwave alert from midday Thursday. According to Météo France, temperatures could push to 33°C to 34°C, locally 35°C, in the capital and the neighboring departments.
Heatwave: Paris and Île-de-France switch to orange alert, and what that means
Paris and the inner suburbs enter orange heatwave vigilance from Thursday, May 28, 2026 at 12:00, while the rest of Île-de-France remains on yellow alert. Expected temperatures, advice and the departments affected. [Read more]
The four latest departments in Île-de-France (Yvelines, Val-d’Oise, Seine-et-Marne and Essonne) have moved to yellow heatwave alert. So what does that mean? Traffic could be disrupted in Paris and Île-de-France public transport.
As explained by the Transilien SNCF Voyageurs blog for Île-de-France Mobilités, rails are mainly made of steel. They are therefore highly sensitive to heat and their temperature rises very quickly. For example, "heat at 37°C outside can raise the rail temperature to 55°C." With such temperatures, the steel tracks can expand and deform. "This weakens the installation and alters the rail-wheel contact essential for train propulsion and braking," the note specifies. To guarantee passenger safety, Transilien SNCF is therefore obliged to take certain measures, such as reducing speed and skipping certain stations.
Transilien SNCF is asking passengers to check train times via the Île-de-France Mobilités app, the transilien.com website, or through SNCF Connect. Passengers are also strongly advised to stay hydrated before arriving at the station and to bring water for the journey. Note that potable water points are available at several Île-de-France stations.
With temperatures topping 33°C on Tuesday, May 26, 2026, Paris and the Île-de-France region remain on yellow heatwave alert. Île-de-France Mobilités has released a map showing free drinking-water fountains near the network’s train stations and stops. [Read more]
Heatwave: Paris and Île-de-France switch to orange alert, and what that means
Heatwave: a map to find free water at Paris train stations
