Air-filled balloons are the best choice for outside arches because they don’t add their own upward tug to the unstable structure of the arch
Let me explain. Temperature, humidity, condensation, direct sunlight and wind all play a role in the longevity of a balloon sculpture. Under ideal circumstances, balloons can last several days to several weeks. Balloons like it cool and dark, so we suggest interior air-filled designs away from windows and heat or A/C vents. In a temperature-controlled environment, we’ve had balloons last well over 5 weeks! However, balloons outside on a hot summer day in the rain may only last a few hours. A properly trained balloon artist will know how to inflate and construct designs to offset Mother Nature, but there is truly no way to ever predict how long a balloon will stay looking fresh.