The British weather is renown throughout the world for being very interchangeable & unpredictable, rain is quite frequent so it's a good idea to carry an umbrella or coat with you when your out & about, while the summers can be quite warm.
Temperatures in Brighton range from 3.45 to 21.15 (Celcius).
Rainfall in Brighton varies from 93.0 to 288.0 (mm/month).