PHILADELPHIA - The first full week of fall will be off to a warm and muggy start across the Delaware Valley.FOX 29's Scott Williams is calling for a high of 80 degrees once we see a break in the morning fog and finally see the sun.By the end of the week temperatures will be starting to feel more seasonal, but not before a few more mild and rainy days,Tuesday looks to bring showers and highs in the upper 70s while Wednesday also promises to be damp with highs in the low 70s.Thursday could also bring more morning rain with a high of just 70 degrees.The weekend is shaping up to be a beautiful one with plenty of sun and highs in the mid-60s in the forecast.AdvertisementFor the latest forecasts and conditions, get the FOX 29 Weather Authority.