The number of drops per second per square foot (square meter of air) varies as there are different types of precipitation:
drizzle - 14 drops per second per square foot (151 drops per second per square meter)
light rain - 26 drops per second per square foot (280 drops per second per square meter)
moderate rain - 46 drops per second per square foot (495 drops per second per square meter)
heavy rain - 46 drops per second per square foot (495 drops per second per square meter)
excessive rain - 76 drops per second per square foot (818 drops per second per square meter)
cloudburst - 113 drops per second per square foot (1,220 drops per second per square meter)
Concentrations of raindrops normally range from 100 to 1,000 per cubic m (3 to 30 per cubic foot); drizzle droplets mostly are more numerous.
Raindrops hardly have diameters larger than 4 mm, because as they increase in size they break up.
The concentration usually decreases as diameters increase. But when the rain is heavy, the visibility does not reduce as much as drizzle does.
To learn more, see this size and precipitation speed chart shared by Usgs.gov.
Rain, we all long for it throughout the year and when it finally arrives we either crib about it or be pleased. Here are some tips on how to enjoy a rainy day shared by Listdose.com.