Llansadwrn (Anglesey)
Weather Station

Rates of rainfall (liquid precipitation)

Rainfall is described in terms of the rate of fall, and not the measured quantity.

Drizzle, very small droplets

Slight (fine) drizzle: Detectable as droplets only on the face, car windscreens and windows.
Moderate drizzle: Windows and other surfaces stream with water.
Heavy (thick) drizzle: Impairs visibility and is measurable in a raingauge, rates up to 1 mm per hour.

Rain, drops of appreciable size and may be described as small to large drops. It is possible to have rain drops within drizzle!

Slight rain: Less than 0.5 mm per hour.
Moderate rain: Greater than 0.5 mm per hour, but less than 4.0 mm per hour.
Heavy rain: Greater than 4 mm per hour, but less than 8 mm per hour.
Very heavy rain: Greater than 8 mm per hour.

Slight shower: Less than 2 mm per hour.
Moderate shower: Greater than 2 mm, but less than 10 mm per hour.
Heavy shower: Greater than 10 mm per hour, but less than 50 mm per hour.
Violent shower: Greater than 50 mm per hour.

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