Reith seems to have equally spaced numerals, but for some reason on BBC Weather's website they don't and are tightly together. It doesn't happen anywhere else on the BBC website. Wonder why they've done this for Weather only as space certainly isn't the reason.
I'd imagine there's a fixed width version for numbers at least, though maybe it's not available as a web font
You'd need it for things like clocks to stop the numbers appearing to jump around due to different width characters.