Na va-nad

Data source and script

The data come from the Météo-France daily or hourly climatological observations published on data.gouv.fr.

The script used for the calculation is available as a GitHub Gist: joseph-sch/5b6399552efa0c431b6a2bfe94a88218.

Summary as of June 24, 2026

Paris stations

Metric	Paris-Luxembourg	Paris-Montsouris
Days above 35°C	6	6
Longest run above 35°C	6 days	6 days
Run start	2026-06-18	2026-06-18
Run end	2026-06-23	2026-06-23
Daytime excess above 35°C	18.1 °C·days	10.7 °C·days
Night excess above 20°C	26.2 °C·nights	17.6 °C·nights
Highest Tmax	38.6°C	38.3°C
Highest Tmin	27.3°C	25.8°C
Days covered	13	13

Summit of the Eiffel Tower (330 m altitude)

Metric	Paris-Tour Eiffel
Days above 35°C	1
Longest run above 35°C	1 day
Run start	2026-06-18
Run end	2026-06-18
Daytime excess above 35°C	0.2 °C·days
Night excess above 20°C	20.1 °C·nights
Highest Tmax	35.2°C
Highest Tmin	27.9°C
Days covered	13

What the numbers show

As of June 24, the Météo-France hourly observations indicate that Paris has already had six consecutive days with maximum temperatures above 35°C, from June 18 to June 23, 2026. At Paris-Luxembourg, a central urban station, the cumulative excess has reached 18.1 °C·days above 35°C during the day and 26.2 °C·nights above 20°C at night, compared with 10.7 and 17.6 respectively at Paris-Montsouris. The difference highlights the role of the dense urban environment, especially in the persistence of hot nights.

August 2003 comparison period

For comparison, the same script was run on Météo-France daily observations for July 25 to August 20, 2003.

Paris stations

Metric	Paris-Luxembourg	Paris-Montsouris
Days above 35°C	10	9
Longest run above 35°C	10 days	9 days
Run start	2003-08-03	2003-08-04
Run end	2003-08-12	2003-08-12
Daytime excess above 35°C	36.0 °C·days	28.1 °C·days
Night excess above 20°C	19.0 °C·nights	35.0 °C·nights
Highest Tmax	40.2°C	39.5°C
Highest Tmin	23.2°C	25.5°C
Days covered	27	27

Summit of the Eiffel Tower (330 m altitude)

Metric	Paris-Tour Eiffel
Days above 35°C	6
Longest run above 35°C	3 days
Run start	2003-08-05
Run end	2003-08-07
Daytime excess above 35°C	18.2 °C·days
Night excess above 20°C	46.1 °C·nights
Highest Tmax	40.3°C
Highest Tmin	28.6°C
Days covered	27

Comparing 2026 so far with August 2003

The June 2026 heat wave is already notable, but it has not yet reached the full August 2003 sequence in the main long-running Paris station. At Paris-Montsouris, the current episode has six consecutive days above 35°C, compared with nine consecutive days from August 4 to August 12, 2003. The daytime excess at Montsouris is also still lower: 10.7 °C·days above 35°C so far in 2026, compared with 28.1 °C·days during the July 25-August 20, 2003 comparison window.

The urban contrast is different depending on the station. In June 2026, Paris-Luxembourg already shows a larger daytime excess than Montsouris, 18.1 versus 10.7 °C·days, and a larger nighttime excess, 26.2 versus 17.6 °C·nights. In the 2003 comparison window, Luxembourg had the higher daytime excess, 36.0 versus 28.1 °C·days, while Montsouris had the higher nighttime excess, 35.0 versus 19.0 °C·nights. The final 2026 comparison will depend on the observations for June 24, June 25, June 26, and the following days.