Our weather is very unpredictable. It's not possible to make an accurate forecast more than a few days in advance.
It doesn't rain as much as you might have heard but you can't guarantee dry weather. I suggest you bring layers and a rain jacket. Hopefully you will be lucky!
British weather is extremely variable and extremely local. We have a term called 'April showers',
London in April is likely to be wet occasionally but not likely to be cold enough to need more than a light coat or a few layers.
Mixed. Average daytime temperature 13 to 15 degrees centigrade; 55 to 59 f. Some showery days; some dry days. It can sometimes be a lot milder in April. Being an island our weather is somewhat unpredictable
www.metoffice.gov.uk
Whole bunch of different weathers. In the UK you can wake up, it could be nice and warm, blue skies and sunshine but then start getting windy and start pouring down with rain with a strong dark overcast and then would be time for lunch. Often the BBC are very inaccurate about the weather as it changes so often.
"Interesting" is the politest way to put it..... can range anywhere from bright & sunny (but with a really chilly breeze) through to still a chance of snow in some places.
English weather in April is particularly well known for being even wetter than usual.... sometimes so bad it can even defeat the best quality "waterproof" outdoor jackets made by the world's finest manufacturer's of proper outdoor clothing.
No one can predict the weather more than three days in advance, anything else is just an educated guess.
http://www.bbc.co.uk/weather/2643743
Its ok ,,,, can be sunny, can be cloudy, can be cold and it could be warm