Skip to content

Rainfall, by the numbers

50 mm in 2 hours

An average rate of 25 mm per hour. Here’s what that amount means, in water and in motion.

Heavy · average intensity

The rain is illustrative. Actual intensity varies within a storm.

The quick answer

25 mm/hrAverage rainfall rate
Total water per m²
50 litres
Depth in inches
1.969 in
Across a 100 m² area
5,000 litres
Adjust in the explorer

Volumes assume no runoff, evaporation or infiltration.

Amount and intensity are different.

50 mm tells you the total rain. Dividing that amount by 2 hours gives the average hourly rate of 25 mm/hr.

This falls in the explorer’s “heavy” display category. Brief peaks could be higher, and weather services may use different category thresholds.

See how the scale works →

What happens on the ground?

Soil, slopes, drainage, earlier rain and the shape of the storm all matter. A rainfall total alone cannot tell you whether a place will flood or whether travel is safe.

For conditions where you are, check official local forecasts and warnings. Use this page to understand the quantities.

Weather data & references →

Compare another amount.

Convert your own measurement