adding Freon, what should be psi be when done? Its is 90 degrees outside

 

You don't charge by pressure, you charge by weight. But you must vacuum down the system first, and after vacuuming, assuming it holds vacuum, which means there are no leaks then you charge the correct weight of refrigerant.

 

Best would be to charge by weight, but if you are topping off:

Looking at this chart, it would be 45-55psi low side, and 250-270psi high side.
No engine speed mentioned, so I would guess idle.

R-134a System Pressure Chart - AC Pro

Looking at page 21-45 of the 1998-2002 Accord Service manual looks like
about 30psi low, and 270psi high. Much lower on the low side than the
standard chart, but Honda calls for 1500rpm for the test.

I would err on the low side, not wanting to overfill, then check the vent temp
and see if it's in range on the chart.