13 August 2026 - Hot day, 38 degrees

I can't believe I'm saying this, but I am beginning to get a fed bit up with the constant hot weather here in the UK. Today it is 38 degrees, or 100F.

For the benefit of my non-UK readers, British heatwaves often arrive with much higher humidity than equivalent temperatures in many other regions. Moist Atlantic air raises the dew point, slowing sweat evaporation and making the body struggle to cool itself. London can exceed 40% humidity on a 35–38°C day, while Madrid might be closer to 20% at the same temperature. This makes UK heat feel far more oppressive. Humidity can make conditions feel 5–10°F hotter than the actual reading.

However, that is not the end of the story. UK housing is designed for cold, damp winters. Walls, insulation, and roofing are optimised to retain heat, not release it. During a heatwave, indoor temperatures climb relentlessly, especially at night, leaving homes like an oven. AND, to make it even worse in the U.S., air conditioning is nearly universal: about 90% of homes have AC. In Europe (including the UK), it’s only around 19%.

So, next time you hear a British person complain about a heatwave, you'll know why!