Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Teardrop Hail
Name: Tina
Status: N/A
Age: N/A
Location: N/A
Country: N/A
Date: N/A 

I teach preschool and would like to be able to answer these questions for future weather units. In a recent storm I noticed that the hailstones were tear drop or triangular shaped. I don't remember seeing such a shape before. Can you tell me about the shape? Why it is different?

Hi Tina

In upper regions of clouds, air temperatures are below 32 degrees Fahrenheit and water freezes. The shape the water freezes in forms the shape of hailstones. So irregular shaped hailstones are more the rule than the exception. And then as they fall to earth, and sometimes get sucked back up into the cloud by uplifting winds, they may add more layers of ice adding to the irregular shapes.

Sincere regards,

Mike Stewart


How the hail is oriented/tumbles as it falls and the forces of the wind upon it determine its final shape. Teardrop shapes are common, as are half spheres with one side (the side that is up while it falls) "scooped out". Hail can form a tear drop shape when it falls without being tumbled or blown sideways by wind (in still air). Air moving past the hail stone as it falls causes water that is encountered to move upwards along the hail (water streams out from the top), resulting in a tear drop shape.

The triangular shape may be just an oddity of how the wind spun the hail around as it was falling.

David R. Cook
Climate Research Section
Environmental Science Division
Argonne National Laboratory

Click here to return to the Weather Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (, or at Argonne's Educational Programs

Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory