Mourners watching the Queen's coffin procession in central London are set for sunshine and 23C highs on Wednesday afternoon - but they are likely to face heavy rain if they are queuing in the morning.
A low pressure that has been over the country in recent days bringing warmer weather and heavy showers is gradually leaving with a high pressure system moving in from the north.
It means that as the week progresses there will be increasingly cooler weather and it will feel notably colder by the weekend with widespread temperatures in the mid to high teens.
