Monday brings the nicest weather of the week with lower humidity, plenty of sunshine and comfortable temperatures.

A significant pattern change arrives beginning Tuesday as heat and humidity steadily build. Dangerous heat is expected from Wednesday through the Fourth of July weekend, with heat index values climbing into the low to mid-100s by Thursday and Friday. Scattered afternoon and evening thunderstorms are also possible late in the week, but the biggest concern will be the prolonged stretch of oppressive heat.

Monday: Mostly sunny with lower humidity and seasonable temperatures. Highs in the upper 70s to lower 80s.

Tuesday: Partly sunny, warmer and more humid. Highs in the mid to upper 80s.

Wednesday: Mostly sunny, hot and increasingly humid. Highs in the upper 80s to lower 90s.

Thursday: Dangerous heat develops with heat index values in the low to mid-100s. Highs in the lower to middle 90s.

Friday: Dangerous heat continues with scattered afternoon and evening thunderstorms possible. Highs in the lower to middle 90s.

Saturday (Fourth of July): Hot and humid with scattered afternoon and evening thunderstorms possible. Highs in the lower to middle 90s.

Sunday: Hot and humid with only slight relief from the late-week heat. Highs around 90 degrees.