Milton Keynes, Thursday 13 August 2026

On the hottest day of the summer, walkers on 70% of Milton Keynes' footpaths faced very strong heat stress.

That is a feels-like temperature of 38 °C or more, for at least an hour.

The code

Reached 38 °C during the day

Air peaked at 36 °C
6am9am12pm3pm6pm

Hours that felt like 38 °C or more

None1–23–45 or more
Not modelled: built since the lidar flight, or under a bridge or roof

How this was made

Environment Agency lidar flown in the winters of 2019–20 and 2020–21 gives the shape of the area; a custom deep-learning model sorts its points into ground, buildings, trees and water. SOLWEIG (Lindberg et al. 2008) follows the sun over them hour by hour on 13 August 2026 and, with the Met Office's 2 km UKV air temperature, humidity and wind, gives the feels-like temperature (UTCI) on each 1 m square. Footpaths are from OpenStreetMap, bus stops from NaPTAN; places built since the flight are greyed. New trees are placed as TreePlanter does (Wallenberg et al. 2022). Urban means the census areas the ONS classes as urban (2021). From a UTCI of 38 °C (very strong heat stress), a walker's core temperature starts to rise within half an hour (Błażejczyk et al. 2013).

© OpenStreetMap contributors · Protomaps · Lidar © Environment Agency · NaPTAN © DfT · Contains OS data © Crown copyright and database right 2026 · Boundaries and urban areas: ONS · Weather: Met Office UKV (CC BY-SA 4.0), weather data by Open-Meteo.com · MapLibre

The code and its references: github.com/JacobWeinbren/mk-heat