This summer we are experiencing a bit of a heatwave in the UK. It isn't much compared to what people are used to in Spain or other hot countries but it is unusual for a British summer. I was explaining this in a chat with a Chilean friend today, and realised I didn't know the Spanish word for heatwave. Fortunately it is one of those words where my first guess was the right one. I just put together the words for heat (calor) and wave (ola) to get 'ola de calor'. This turned out to be the right word, but I could also have used canícula. This is similar to the French word for heatwave - canicule - which I always remember since it sounds a bit like saying 'I cannae cool down'.
heat - calor
wave (in the sea) - ola
heatwave - ola de calor, canícula
heatwave - ola de calor