The weather forecast for the Coronation weekend has been announced by the Met Office - and showers are on the cards.
Forecasters said it is difficult to confirm exactly what the weather will be like at the moment but added that rain may fall on the King's parade on Saturday.
It looks as though it would be a good idea for royal fans to wear their raincoats and take their brollies.
Met Office spokeswoman Nicola Maxey said: "We've got quite a showery picture. Friday is going to be a mixture of heavy rain and showers and thunderstorms."
She said London may stay dry on Saturday morning, but that showers may develop through the afternoon.
The coronation ceremony at Westminster Abbey will end at 1pm and the newly crowned King and Queen will begin the procession back to Buckingham Palace in the gold state coach.
Some 4,000 sailors, soldiers, aviators and other military personnel from across the UK and the Commonwealth will accompany Charles and Camilla on their return procession.
There will be more than 1,000 route liners from the Army, RAF and Royal Navy.
Charles and Camilla are expected to enter Buckingham Palace through the centre arch at 1.33pm.
They will receive a salute from the military in the palace gardens at 1.45pm, and then at about 2.15pm they will be joined by members of the royal family on the palace balcony to watch the flypast.
Ms Maxey said: "At the moment it looks like, as I say, the morning should be relatively dry with some sunny spells in London, but the afternoon could see showers developing in London.
"But long lead time, so as always the message is to keep an eye on the forecast and check it regularly because the detail will become clearer as we get nearer to the day."
Meanwhile, it is expected to be warm and humid with temperatures reaching as high as 20C.
Ms Maxey said: "We could certainly see temperatures, high teens, maybe 20C for London, and mid to high teens for elsewhere in the country as well.
"Whether you feel warm or not will depend on whether you get a break in the cloud and a spell of sunshine.
"In which case it's going to feel great, but under a shower it might not feel as nice."
The Met Office also shared the maximum and minimum temperatures of previous Coronations, including that of George VI and Elizabeth II.
The maximum temperature on August 9, 1902, on Edward VII's Coronation, was 16C, while the minimum was 9.1C - and there was 0.5mm of rain.
On June 22, 1911, on George V's Coronation, the high was 17C and the minimum 12.8C, with 0.3mm of rain.
When George VI was crowned on May 12, 1937, the daily maximum temperature was 14.2C, and the minimum 6.2C, with 8.2mm of rain.
And for the Coronation of the King's mother Elizabeth II, on June 2, 1953, the daily maximum temperature was 11.8C and the minimum 6.8C, with 2.6mm of rain and 1.2 hours of sunshine.
