why are there no seasons in jupiter?

Jupiter has no seasons because the axial tilt of only 3 degrees.

This means there is literally no difference in what you would experience if you went to jupiter for 2 months versus 6 months, or a year.

Orbits around the sun are uniform and unchanging with an axis that does not change, so do not expect to have any kind of seasons during your visit. The climate remains generally stable and constant with a cycle that lasts for 10 Earth years and will last until 2020 where the next one will take place. One polar ice cap pre-dates all others on Jupiters moons by eons because it was formed at least 4 million years ago  as micro fractures joined forces together and metamorphosed into solid