All of section PC13 is located outside without an overhang above for shade or relief from rain.

PB vs. PC
At Fenway Park, PB sections are located directly behind PC sections and are under the roof

PB Sections

If you are looking for some protection from the elements on the upper level of Fenway Park, consider rows C and higher in any of the PB sections as they have a roof above covering you from the sun and rain. Infield and Outfield grandstand sections also provide a roof above and are good options for relief from inclement weather.