Charlie,
The sunlight (heat) shouldn't raise the pressure at all unless the park has a check
valve in the hydrant. Excess pressure will simply cause the water to back up into
the line. However, sunlight and heat soften the vinyl material that the hose is made
from, so it will be not quite as strong when warm.

I won't argue whether the hose will stand 100 PSI, I've never tried it. It does seem
like a good hose wouldn't have a problem with that kind of pressure; it's common for
city water to exceed 65PSI.

Charlie/Betty Burke wrote:

> "
>
> Actually you do need to be concerned about the hose. If by chance you are hooked
> up to a park with 100 psi and you are not using the water during the day, say
> while you're out being a tourist, the sun will heat the water, which will raise
> the pressure even more. Garden hose often don't burst because they typically
> spent little time under full pressure with the sprayer or sprinkler head turned
> off.
>