What should I wear when going to London in late May?

Because I go to school in London, I feel I have to say that the weather in London is very changeable. In May, the temperature is generally around 20 degrees Celsius when it is hot, and it may be 7-8 degrees Celsius when it is cold. The temperature difference between day and night is a bit big, it’s very windy outside, and it often rains in London, so when it rains and winds, it’s colder. I suggest that you wear a windbreaker style jacket with a slightly thicker one, and underneath it can be a girl’s skirt, a boy’s shirt or jeans. Because London also has heating, it will be cold when you go out, so it is better to prepare more clothes. The temperature here is changeable and it is easy to catch a cold.