Groundhog Day Shadow Tracker

Physical Astronomy Tool by Daniel Cummings

Groundhog Day Shadow Tracker Lesson Plan
It’s Groundhog Day!

What better way to celebrate Groundhog Day than to Build your own Groundhog Day Shadow Tracker

Sun Tracker Window Gel Cling and Stickers to track the Sun

UPDATE: We now sell an astronomy gift called the Sun Tracker that teaches you the same Basic Astronomy Lesson that the Ground Hog does! You can learn all about the apparent movements of the Sun and the analemma.

It’s called the Sun Tracker and you can purchase one right from this website.

Let’s do some Physical Astronomy. The experience will help you to understand the movement of the earth and sun through the seasons. You will build a scientific instrument that is also a fun garden decoration and you will be able to track the Groundhog’s Shadow all Spring!

Setup and Process

Start with this cutout pattern and attach it to a post made of metal, wood, or plastic.

Groundhog Day Shadow Tracker Cutout Pattern


  1. Foam core or construction paper
  2. Scissors or hobby knife – foam core
  3. Wooden or plastic stick 12-24″
  4. Tape or glue for connecting Groundhog
  5. Permanent Markers or weather proof paint for decorating (Groundhog will stay outside)

Help the Groundhog find its shadow

On a sunny day at noon (near to Groundhog Day), stake the Groundhog in the ground and mark where the sun shines through the hole.

Groundhog Day Shadow Tracker placement and sun beam

Time goes by

Every week or so, the sun will climb higher in the sky and the groundhog’s shadow will get shorter. You can visit the shadow tracker weekly and add a new marker each time. You will see the shadow getting shorter and shorter.

Groundhog Day Shadow Tracker showing shadow getting shorter with time