Outdoor water birthday party

Outdoor Water Fight Party

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Party Plans

We just celebrated my boy’s 8th birthday with an awesome party! Since it has been pretty hot here lately, we wanted to do a water fight birthday party. This is a perfect party to do in your own backyard and you can adjust how you do it depending on your space and what you have. It’s the perfect DIY party for summer birthdays, even though it’s technically still spring here. Thankfully, the weather cooperated great for us and we had a perfect day for an outdoor party. Plus birthday parties for boys need an outlet for some extra energy!

You might want to choose your guests carefully for this birthday party. We found that about 8 is a good number to be able to have a good fight without breaking in to mass chaos. Also, be sure that the guests you invite can appreciate the roughness of a water fight and won’t mind getting sprayed down with a water gun or having water balloons thrown at them. Luckily all the boys we invited to this water party had no problem with that.

For the invitations, get a pack of small water guns and attach a tag with all the party details, such as date, time, location, and RSVP information. You can include a playful message like “Get ready to soak up the fun! Join us for an epic water fight birthday party!” Then give these to each guest with instructions to come wearing a bathing suit and to bring a towel.

water gun bulk for party

Party Decorations

Since this birthday party will be outside, you really don’t need much in the way of decorations. Instead of traditional balloons, we had water balloons everywhere. Fill up every bucket, cooler, etc, that you can find and stash them around the party area. I even used our sleds to hold water balloons. You will definitely want these self sealing water balloons. (If you can find the off brand kind, I’ve found they are usually just as good!) How many will depend on your guests and what you plan on doing with them, but I planned for at least 50 per guest. If you haven’t tried these quick fill water balloons yet, you are going to fall in love! You can literally fill hundreds in a few minutes and no more tying knots!

self sealing water balloons for party

We found that with hundreds of water balloons everywhere, a pool full of water, a squirt gun station, a slip-n-slide set up, a pinata hanging, and of course the food table, we didn’t feel the need for additional decorations! But if you would like, you could set up beach towels and umbrellas as seating areas and decoration or hang banners around the party area with appropriate themed phrases like “Let the Water Fun Begin” or “Splish Splash, It’s a Water Bash”.

For the water party set up, scatter water guns and water balloons around the party area to add to the excitement and encourage guests to engage in the water fight. We filled a baby sized swimming pool and put it in the middle of the yard. This made a great center area and worked good as a play area while waiting for all the guests to arrive. Even though the boys are a little older, they had fun splashing around in it. It worked as a kind of introduction to the water before getting completely soaked! You might even have two pools if you have a lot of guests at your party.

*Tip: Fill the pool a couple of hours before the party to give the water time to warm up. Our water comes out of the hose freezing cold, so this helped a lot!

pool water fight party

Birthday Party Games & Activities

There are SO many activities and games that you can do for an outdoor water party. Here are the ones that we chose:

  • Squirt gun fight: we started the party with a casual squirt gun fight. We had a variety of squirt guns and let everyone “choose their weapon” (starting with the birthday boy).  We went over a couple of rules like no squirting in the face and make sure you put some distance between someone before blasting them, then it was a free for all. If you would like this to be more organized, you could split into teams and even give everyone colored team vests.
  • Water Balloon Hot Potato: Gather the guests into a large circle. Start some music and begin passing around a water balloon. Randomly stop the music and whoever is holding the balloon when the music stops has to pop it over their head! (We found they loved this and wanted the music to stop on them.) You could play that the person it stops on is out and keep going until there is one left, but we just kept everyone in and didn’t have a “winner”.
  • Slip and Slide: If you don’t already have a slip and slide for your party, I recommend getting one like this. It is fun having the lanes so they can race, plus there will be less waiting in line! Also, the longer the better, and you definitely want those inflatable body boards to slide down on.
    • slip and slide for water party
  • Capture the Flag: The kids all said this was the funnest part of the birthday party! If you know how to play capture the flag, this is just a version where instead of tagging, you throw water balloons. To prepare, I made a red and blue “flag” (out of scrap fabric and a stick) and stuck them in opposite sides of the yard, representing each team’s “base”. Each side also had a large stash of water balloons (held by a plastic sled!). We divided the group into two teams (this is where these vests would come in handy again). The goal is to try to get the other team’s flag back to your base. But if you get hit with a water balloon, you have to go back to your side before you can try again. You can adjust the rules to make it work for you.
  • Pin the balloon on the birthday boy: My son came up with this one. The guests stand in line and take turns trying to throw a water balloon at the birthday boy. He can try to dodge. Everyone loved getting to try to “pin” him.
  • Water balloon fight: To use up the rest of the water balloons, we just let the go wild and have a water fight with no rules, just fun.
    • water balloons birthday party fight


  • Piñata: last, because we were outside, it just made sense to do a piñata! Tip: if you have chocolate in your piñata, don’t set it up until right before the party so it doesn’t melt!

Party Food & Drink

We set up a table with chairs off to the side of the yard for the food so it wouldn’t get wet or tripped over in all the water fight action. Our goal was to not need any plates or forks. Great snacks for outdoor birthday parties are chips and crackers because they can be set out the whole time and grabbed easily, so we had a a few bowls full of those. We had sliced chilled watermelon to help with hydration, but the favorite was a cooler full of ice and otter pops (or any kind of Popsicle). They loved the “all you can eat” style popsicles. Lemonade or juice boxes are good for drinks, but we made sure to have water options, too.

otter pops popsicles for outdoor party

Birthday Party Favors

Obviously, the birthday guests will get to bring home all their candy that they get from the piñata. We made sure to stuff it with lots of goodies so everyone would have plenty to take home. Also, have bags with their names on them for each guest to fill with candy when it burst open. That gives them an easy bring-home gift.

pinata outdoor birthday party

If you didn’t use mini squirt guns for the invitation, it would be great to use them here for a party favor. More ideas for birthday party favors for an outdoor water party would be: beach balls (probably deflated), sunglasses (you could also give these earlier if you need them during outdoor play), or personalized water bottles with their name on it (this would make keeping track of cups during the party so much easier).

Remember to have plenty of towels and a designated drying area for guests to dry off after the water fight. Also, ensure there is adult supervision to ensure safety during the festivities. Kids can get pretty wild. Have a fantastic water fight birthday party!


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