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Rainfall, by the numbers

10 mm in 12 hours

An average rate of 0.833 mm per hour. Here’s what that amount means, in water and in motion.

Very Light · average intensity

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

The quick answer

0.833 mm/hrAverage rainfall rate
Total water per m²
10 litres
Depth in inches
0.394 in
Across a 100 m² area
1,000 litres
Adjust in the explorer

Volumes assume no runoff, evaporation or infiltration.

Amount and intensity are different.

10 mm tells you the total rain. Dividing that amount by 12 hours gives the average hourly rate of 0.833 mm/hr.

This falls in the explorer’s “very light” 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 →

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