In warm weather, latex balloons will typically only last outside for a day. As you know, sun, wind and heat will biodegrade the latex.
With that said, however, there are tricks you can do to raise your odds of getting them to last more than a day outside.
1) Use only high quality balloons like Qualatex. I've also heard that some people have used Bellatex and Tilly balloons with some success. Quality makes a huge difference.
2) Avoid using latex balloons whenever possible. After a few days outside, we have seen them completely disintegrate when touched.
3) Qualatex' Polyurethane Duo balloons are designed for outdoor use. They will last longer and look better for extended outdoor use than any latex or foil balloon. They are a bit more pricey but can really take away the headache of shrinking and disintegrating balloons. For larger Duo balloons like 18", it may be cost effective to rent them. The Duo balloons can also be used to leverage small latex balloons. Underinflate your smaller latex balloons and use the lift power of the big balloon to raise them.
4) Always underinflate to allow balloons to expand when absorbing heat. We've found the method that works best is to over-inflate the balloon and then release air until the balloon is slightly underinflated. This helps the balloon to breathe and expand more easily, and it is not as brittle. Underinflating does little good unless you overinflate first.
5) Use balloons two sizes larger than you would normally use.
6) Inflating balloons with the same temperature air as they will encounter outdoors can actually help to retain their shape better.
7) Helium does not work well outdoors in the heat. If you need to use helium-filled latex, try to use large balloons like 24" and inflate to only around 16". Over- inflate with air first, release the air and then re-inflate with helium. You don't want to waste your helium when you pre-inflate.
8) After your balloons are inflated, consider applying a product called "Balloon Shine." It can protect your latex balloons from the sun's UV rays. It's best to experiment with this days before to see if it will work.
9) While Hi-Float is used to make balloons float longer, it is not generally meant for outside use. If you want your balloons to float longer outside, you should plan on doing daily touch-up work to your balloon arrangements. Be sure to include this in your budget.
10) Balloons simply will not last outdoors overnight. As the cold air shrinks the balloons and then they expand in the sun the next day, they will pop like crazy. This can be avoided by simply bringing all balloons indoors in the evening.
11) Use white balloons as much as possible. They reflect the sun and fade less.
12) Avoid darker balloons. They will absorb heat and pop faster. If you need darker colors in your balloon decor, use ribbons to accent in a darker color.
13) Keep in mind that extreme heat speeds up the balloon leakage process. So, in temperatures close to 100 degrees, the helium will escape much faster, drastically reducing float time. If you can find a way to shade balloons, it can slow the process, somewhat.
14) Do not use water to cool down balloons. As the water dries on the latex, it becomes slightly sticky. Balloons can stick together causing them to pop as balloons they expand in the heat.
15) Mylar foil balloons last longer outdoors than latex. Just allow for normal expansion and shrinkage. The downside is that in the hot sun the foil will not hold its color or sheen. There will be a noticable difference by the end of the day.
16) Whenever possible, use some kind of framework to give your balloon decor structure that can withstand wind and heat. This can also be helpful for helium-filled balloons that will lose float time in the heat.
17) We've found that if balloons are going to pop in the heat and sun, the will usually do so within the first hour. So, you'll have a pretty good indication of whether it will work if you set up early.
While it can be difficult to do balloon decor outdoors in the heat, it is certainly not impossible. Just use the above tips to greatly improve your odds.
Passionate about advertising balloons, Kathryn Parisse is editor of The Balloon Newsletter. Subscribe and get answers to all your balloon decor, twisting, and advertising questions at aBalloonaDay.com.