A typical raindrop is 2 millimeters (2000 microns) in diameter.
Here's a breakdown to understand the size of a raindrop in relation to other atmospheric particles:
Size Comparison of Atmospheric Particles
| Particle Type | Diameter (microns) | Diameter (millimeters) |
|---|---|---|
| Small Aerosol Particle | 1 | 0.001 |
| Large Aerosol Particle | 100 | 0.1 |
| Cloud Droplet | 20 | 0.02 |
| Typical Raindrop | 2000 | 2.0 |
As you can see from the table, raindrops are considerably larger than cloud droplets and aerosol particles.
Understanding the Size Differences
- Aerosol Particles: These are tiny particles suspended in the air, like dust, pollen, and pollutants. They range in size from 1 to 100 microns.
- Cloud Droplets: These are much larger than aerosol particles. They form when water vapor condenses onto aerosol particles. However, cloud droplets are still very small. A typical cloud droplet is about 20 microns in diameter.
- Raindrops: Raindrops are formed from cloud droplets through a complex process of collision and coalescence, where cloud droplets bump into each other and merge to form larger drops. A raindrop is significantly larger than a cloud droplet. Raindrops are typically around 2000 microns (or 2 millimeters) in diameter.
Raindrop Formation
Raindrops form when water vapor in the atmosphere condenses into droplets around microscopic particles (aerosols). These tiny cloud droplets grow further through collisions with other droplets and water molecules. When they become heavy enough, gravity pulls them down as rain.
Therefore, while the initial condensation starts with tiny droplets around 20 microns, a fully formed raindrop that you see and feel when it rains is around 2 millimeters in diameter.
