Storm Ophelia, a former hurricane which is now battering parts of Ireland, appears to have sent the sun red.
In addition to strong winds, ex-hurricane Ophelia brought with it large amounts of Saharan dust as it headed towards the UK.
"So it's most likely the appearance of sunset at midday is caused by the particles scattering the light and giving the appearance of a red sun".
London's Science Museum reassured twitter users that it's not the apocalypse.
Readers have sent in their pictures of the odd phenomena.
In Northern Ireland, 15,000 spent Monday night without power, the BBC said.
The Irish Meteorological Service advised people to stay indoors on Monday, and were asked to remove any loose items, like patio furniture or rubbish bins, for fear that they could turn into "wind missiles". One woman and a man died when trees fell on their cars.