I've been reading up on the summer of 1976, and found this link, which might be of use to MWPP-era writers.
From the Swindon Advertiser Conditions were similar across England (don't know about Scotland, sorry, but I assume it was similar). Looking at it, I don't know if it would seem like such a hot summer to someone from a fiercer climate, but it was a real shock here. We've had summers which are almost as hot since, but we still find them exceptional. Summers are supposed to be grey and wet. 1976 is more than just a hot summer in the British imagination. Everyone has a story about what happened in their own part of the country - heathland that burnt for days, plagues of insects, rivers that vanished, tarmac melting on the motorways. I wasn't born, and I still instantly associate 1976 with the heat.
This one has more statistics but less about the effect of the heat.
Also, the
ever-trusty BBC.
Hope they're of use to someone :)