UK tabloid front pages about heatwaves are almost always in Fahrenheit.

The Daily Express routinely uses Fahrenheit when reporting heatwaves or blizzards on the front page - most of the other UK tabloids rarely have a weather focused front page.

Faranheit only for heatwaves. For blizzards they always use centigrade. Without fail.

Why? So the temperatures seem more extreme?

Precisely. A really hot day sounds more impressive when you say 82 Fahrenheit, rather than 28 Celsius. Similarly, you get down into the negative numbers way sooner with Celsius (since freezing is 0, rather than 32).

Just makes for better headlines, although almost everyone uses C now.

You need to talk to more people over 55 years old then (the metric system was taught in schools from 1974 onwards).