Saturday's Coronation was supposed to give the public a chance to get together in the spring sunshine and feel patriotic - but the weather forecast is likely to dampen those spirits.
Rain was forecast for the majority of England throughout Saturday, according to the latest maps, and will combine with relatively warm temperatures to produce a grim, muggy Coronation Day.
It'll form part of a horrible nine-day stretch of consecutive rain for some parts of the UK, including London.
A band of showers will head northwest from Saturday morning, starting from Land's End in Cornwall.
By 10pm, rain was likely to fall as far north as Glasgow and Newcastle-upon-Tyne.
Thunderstorms were also likely for most of England on Coronation Day, according to Ventusky.
The Midlands had the greatest chance of storms, peaking at about 4pm; albeit starting from 1pm.
However, everywhere between Leeds and Canterbury were at risk of thunderstorms.
The warning also stretched in width from the east coast of Norfolk, right the way through to the west coast of Wales.
British Weather Services' senior meteorological consultant Jim Dale told the Mirror: Showers will be the name of the game for Saturday, and thundery in places.
"It'll be warm enough, though. Highs of around 18C-19C in the South and 14C-16C in the North."
Mr Dale urged the public to take precautions if they were planning on heading outside to celebrate the Coronation.
"If you're going out on Saturday, take a mac, take a brolly, and take an updated weather forecast with you.
"If thunderstorms are mentioned, avoid sitting under trees, in open parks/spaces, on open stretches of water [lakes etc.] and on ridges of hills.
"Be safe and in comfort rather than sorry and in the ultimate discomfort!"
The South-East of England was forecast to have the warmest Saturday in the UK.
It could hit 19C in some parts of Kent and Essex, although it could also reach 17C in Glasgow.
On the other end of the scale, Aberdeen was forecast chilly highs of 9C, and the South-West won't get past 13C, weather maps revealed.