On Thu, 20 Jul 2017 12:13:43 +0100, James Wilkinson Sword wrote:

What do you believe weather forecasters mean when they say "40% chance of rain"?

1) It will rain for 40% of the day.
2) There's a 40% chance it will rain at some point.

I googled it and apparently it depends on the forecaster? 1) and 2) are completely different meanings.

Unless there is high pressure stuck over us you can go to 7 UK forecast
sites and get seven different percentages or timings. They all claim to get
their information from the Met Office. I don't believe that all seven have
in-house meteorologists so who makes it up?
--
Jim S