SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/cloud-droplet-speck

What is at the center of nearly every cloud droplet?

A tiny particle, such as dust, salt, or smoke, where water condenses.

Start playing free

  1. A tiny bubble of sunlight
  2. A frozen raindrop in every case
  3. A speck of dust, salt, or another particle ✔

Why: Water molecules need a tiny surface on which to gather. When moist air cools enough, water vapor condenses onto dust, salt, smoke, or another cloud condensation nucleus and forms a droplet.

Huh, didn't know that: NOAA says the speck at a cloud droplet's center is about 1/100th the size of the droplet.

The dad joke
It was raining cats and dogs. I almost stepped in a poodle.
Like this card?
Play the game

References

Answer: A speck of dust, salt, or another particle. Water molecules need a tiny surface on which to gather. When moist air cools enough, water vapor condenses onto dust, salt, smoke, or another cloud condensation nucleus and forms a droplet.

  1. How Clouds Form www.noaa.gov/jetstream/clouds/how-clouds-form
    Every cloud droplet has a speck of dirt, dust, or salt crystal at its core.
    Checked 2026-10-11.

Think this answer is wrong? Tap "Challenge this answer" on the card in the game and tell us why.

Test yourself in the game

How Things WorkDoes lightning ever strike the same place twice?How Things WorkHow hot can lightning heat the air around it?How Things WorkWhat causes the sound of thunder?

That's stuff everyone should know.