Thunderstorms happen when raindrops and hailstones crash into each other and create an electrical charge in a cloud. Lightning is a giant spark of electricity escaping. The air becomes very hot and expands quickly, which causes a bang like an explosion (thunder).
A rainbow is an arc of colour in the sky that you can see when the sun shines through falling rain. The pattern of colours starts with red on the outside and changes through orange, yellow, green, blue, indigo to violet on the inside.
Weather in the UK >