mizzle

a fall of tiny water droplets between heavy mist and an outright shower — too thin to need an umbrella but enough to soak your jacket if you stay out long.

• drizzle

  the standard, more common term across both British and American English

• mist

  tinier droplets that hang in the air rather than fall; usually doesn't wet you

• Scotch mist

  British informal — a very fine drizzle with low cloud, often in upland areas

• downpour

  heavy, hard rain — the opposite end of the rainfall scale

• cloudburst

  a sudden, violent fall of rain

(of the weather) to send down very small water droplets — lighter than ordinary rain but more than a passing mist, the kind of weather you only notice once your hair starts to feel damp.

• drizzle

  the everyday equivalent — preferable in writing and in American English

• spit

  British informal — used when only a few odd drops are falling

• spritz

  very light intermittent rain; closer to a fine spray than a steady fall

• pour

  to rain very heavily — the opposite intensity

• bucket down

  British informal for heavy rain