How weird was the Med Sea heatwave?

In early July, the Mediterranean Sea experienced a marine heatwave. The surface of the water reached temperatures of 30 degrees in some places.
A social media post at the time claimed that some of these sea temperatures were so different to the normal sea temperature at this time of year, that the sea was experiencing a “1-in-216,000,000,000-year sea temperature anomaly”.
This would suggest that the likelihood of the event was on a timescale far longer than the amount of time the entire universe has existed.
Is the claim true? Dr Jules Kajtar, a physical oceanographer from the National Oceanography Centre, takes a look at the statistics.
We heard about this story because a listener spotted it and emailed the team. Get in touch if you’ve seen a number you think we should look at. moreorless@bbc.co.uk

Presenter: Lizzy McNeill
Series producer: Tom Colls
Production co-ordinator: Rosie Strawbridge
Sound mix: Neil Churchill
Editor: Richard Vadon