do the rains start again at any point in giza because i went to find the poster and the rains had stopped

If you are beyond a certain point in the game, the Plains shift between wet and dry every hour or so.

After the events at the Stilshrine of Miriam, the Giza Plains weather switches. It will be dry for 2 hours, and rains for 1 hour. The weather will switch when the game clock reads <hours>:00:00.

If you enter the giza plains at :59, it will not change until you leave the area and come back.

Also, talk to "weather eye" in the rabanastre south gate if you want to know how long it will be until the weather changes.

But he doesnt give you a specific time, he will just tell you wether you are less than 1 or less then 2 hours away from the next switch

thanks i got him anyway :D

"Ooohhhh...a gil snappah....they very tastey..."

Mad props to anyone who gets the reference!