Taking the local weather in Filadelfia into account is an important factor for planning your visit, especially if you plan to spend your trip by the pool. The hottest months are usually August and September, with an average temperature of 15°C, while the coldest months are January and December, with an average of 15°C. The rainiest months in Filadelfia are May, April, October and June, with each month seeing an average of 729 mm of rainfall.