Temperatures are already warm this morning with most places well into the 70s. Philadelphia will be rising into the 80s by 8 AM, and with dew points in the mid to upper 60s, it will feel quite uncomfortable. Dew points may come down a bit this afternoon as the wind mixes the air, but with a high in the upper 90s, that will be hardly noticeable.
By midday, Philadelphia will already be hot with temperatures in the lower 90s. Look for hazy sun throughout the day with a touch of humidity. It will be a very hot finish to the afternoon with a high temperature of 98 degrees. The record high today is 102 degrees, set back in 1988. This record should be safe, but we will come close. I wouldn't be surprised if Philadelphia actually ends up at 99 or 100 this afternoon, but I'll stick with 98 for now. Similar temperatures are expected on Wednesday, but the humidity will become oppressive by then. Stay cool in the A/C this afternoon -- if you don't have it, try to go somewhere that does.