The overall location in this book would be New York. I imagine it to be highly populated since it's a big state.
This book mostly takes place at Camp Half Blood which is a camp for demigods the kids of the gods. This is because after Apollo is turned into a mortal and sent down to earth from Olympus, he decides the safest place to go would be the camp itself.
My novel takes place around the same period we're living in right now. I imagine it to be pretty cool knowing the fact fact that gods could be living above us.
The weather in New York isn't really hot or cold. The average temperature is 55 degrees during the day and around 38 degrees at night. Most of New York is dominated by farms, forests, rivers, mountains, and lakes.
In New York, it is highly populated my mortals but since most of my book takes place at Camp Half Blood, thats where most things in the book happens at. Camp Half Blood is not highly populated at all. There are only 19 demigods at the camp because most are at home spending Christmas with their family's.
Some objects that contribute to the time stamp would be, the Prius (car) in the beginning of the book, the cell phone that Percy uses, and the type of buildings since it said skyscrapers in the beginning of the book.
The mood around the camp is more serious and aware since disappearing's have been taking place. This creates a worried tension and atmosphere around the camp.
If Apollo had not been cast down to earth in New York, he would have been able to travel to camp Half Blood because the camp is located in New York.