If you have a kid, chances are you do a few fun things for the Halloween season besides trick or treating. Did you know that Halloween is an awesome time for neat STEM activities and science experiments. Creepy, spooky, gross, and super cool science is also amazingly easy to do at home or even in a classroom. Last season we put together 31 Days of Halloween STEM Countdown. This year we have the Halloween STEM Activities Calendar available as a free printable!


Halloween STEM Activities calendar countdown and free Halloween calendar printable for kids featuring halloween science experiments, Halloween slime recipes, and Halloween STEM activities!


I am so glad you asked because STEM is one of the coolest things out there for young kids to get started with early. STEM stands for science, technology, engineering, and math. Read more abut STEM here with our resource guide.

A good STEM activity will intertwine two or more of these disciplines to make an awesome learning opportunity filled with problem solving, critical thinking, and experimenting. Read more here on valuable STEM lessons.

Now how can you add a Halloween twist to pretty classic STEM activities? It’s all in the accessories, colors, and wording you choose! Brains, spiders, eyeballs, ghosts, zombies, and pumpkins make for amazing Halloween themed STEM activities.

HINT: You can use this concept of colors, accessories, and themes for to turn any classic science or STEM activity into a specific holiday themed one. See our Christmas STEM countdown too.


Below you will find the links in order of the days listed on the calendar. You can download it below by clicking on the big black button that says download here.

I will also add a few more resources for both pumpkin and Halloween science activities.  You can add in or exchange for those activities you might not want to do.

Feel free to mix up the days, try just a few, or make up your own calendar from some of the other resources we have provided for you. Check out the bottom of this post for all sorts of great ideas.

Halloween STEM Activities Calendar Countdown for Kids


I designed this calendar with kindergarten through early elementary age kids in mind. Many of the activities can be used with multiple ages at the same time. Just use your best judgement.

Alternatively, kids younger and older depending on ability and adult assistance can modify any of these activities and still have lots of fun. Also make sure to check out the extra resources below for ideas perfect for preschool age kids too.

One of my favorite themed STEM activities to set out is our holiday tinker trays. This is an open ended exploration tray or bucket filled with easy to use materials. Hopefully it will spark curiosity in your junior inventor or engineer. Here’s our Halloween themed tinker kit!


Click on any of the links below to learn more about each activity, the set up, supplies, and even a little science behind the fun. You can grab your free printable calendar at the very end!


Start out the season by carving your own pumpkin Jack and wait to explore the rotting science that will inevitably happen!

At the same time set up a pumpkin investigation station for your pumpkin!

Build a super simple Halloween themed catapult and experiment with different spooky accessories or pumpkin candy. This awesome Halloween STEM activity includes plenty of experiment suggestions, science, and fun!

Test your chemistry with mini pumpkin volcanos and explore the classic baking soda science with a Halloween theme twist.

Fluffy slime is all the rage and we especially love it with a zombie theme. Zombie fluffy slime has been a real hit around here. It’s actually quite creepy. You have to see the pictures.

A fun way to test your engineering skills is with our ghostly structures engineering activity that we created using dollar store supplies.

Got peeps? Want to make ghost peeps disappear? Cool science and simple candy science activity the kids will love.

Bubbling pumpkins, bubble science, and pumpkin science are awesome for fall in one easy to set up activity! Even try a Jack O’Lantern!

Make ghoulish slime in a white pumpkin. We have tons of easy slime recipes and slime is pretty awesome for Halloween.

Chemistry, potions, wizards and witches are perfect for Halloween science. Check out our Wizard’s Brew thermogenic science experiment using household supplies.

Grab a spooky cup and create an even spookier liquid density tower to explore physics. How many different layers can you stack on top of each other? Density is really a great basic concept that also includes sink/float.

Make your own Halloween tangrams and come up with your own neat Halloween themed puzzles or try some already out there.

Spidery goop is perfect for Halloween. Kids can explore a Halloween themed non-newtonian fluid filled with spiders in this ultra simple kitchen science experiment.

Like crafting and want to combine crafting and STEM, check out this robot spider STEM craft idea.

Balloon science, ghosts, and Halloween combine for a fun and easy science activity with blowing up spooky ghosts. Very simple to set up but a great chemistry demonstration on gasses.

Let’s throw a little technology into this Halloween STEM activities calendar countdown by making your own Jack O’Lantern brush bots.

This one is just for some great novelty science, and we call it fizzy eyeballs! Alternatively, you can check out this other fizzy Halloween science activity. If you need an activity for younger kids, it’s perfect.

Explore static electricity with a ghostly theme for another awesome Halloween themed static electricity physics activity.

Continue exploring physics with Halloween themed rock painting. I bet you didn’t know you could combine physics and painting at the same time?

Make edible candy corn slime dough! A little bit of a sweet treat to check out chemistry in the kitchen,

Spiders are such a creepy theme for Halloween, but we live with them all year round! Explore more with these spider STEM activities.

Now this one was creepy fun. Make and dissect a gelatin heart for intriguing, edible science. We didn’t actually eat any of it but we did learn a little bit about semi-solids exploring this cool Halloween science activity.

An erupting white pumpkin Jack O’Lantern is a take on our pumpkin volcanos but with a fun Halloween twist. Explore more with chemistry this season.

Create your own potion’s table! This is an awesome experience for the junior scientist and can lead to some crazy concoctions. Prepare for a little mess, but my son had a blast and it was definitely worth it.

Need a quick engineering project, check out this super simple and fun ghost stack STEM activity that kids of all ages can really get into and even work together doing.

Make fake snot, why not? My eight year old son loves anything to do with farts and snot. Why not make some edible snot for science and sensory play. Gross science at it’s finest.

Make ghostly bubble towers and learn more about bubble science with a ghostly theme!

Can’t forget the vampires with an edible/ taste safe vampire’s blood slime or goo recipe. Explore the science behind fiber.

Melting ice is a fun and simple science activity for young kids, and melting an icy brain is even cooler. Now we have ours freezing in the freezer right now so stay tuned.

Another fun witch’s fluffy slime recipe made right in a witch’s cauldron. You can see we love our fluffy slime.

Got candy? Let’s throw in a little math with candy graphing.

The last day of the Halloween STEM activities calendar has to showcase all the ways you can use that huge amount of leftover candy. We have tons of Halloween candy science ideas you will definitely want to try.

Halloween Candy Science Experiments for Halloween STEM Activities Calendar

BONUS: Glow stick science. Every one stocks up on glow sticks for Halloween night. Learn a little bit about the science behind them and conduct a quick experiment with the kids.






Halloween STEM Activities Calendar Free Printable Countdown To Halloween with Science Experiments and STEM


Thanks for doing us! We hope you have a happy and safe Halloween season filled with good STEM fun! Get yourself ready for Christmas early this year with either or DIY LEGO Christmas advent calendar or our 25 Days of Christmas STEM calendar!