Our heat indices have been reaching around 100 the past few days. We won't see such a severe heat index for your Sunday. The actual high temperature will be around 91, with a heat index topping off in the mid 90s. This week our temperatures will consistently reach the lower 90s with heat indices in the mid-to-upper 90s and overnight low temperatures in the low 70s. With daytime heating a pop-up shower or storm will be possible in the afternoons of this week.