After one more day of seasonable temperatures, increased heat and humidity will return for the last weekend of July. Highs this weekend will range from lower to mid 90s east of I-29, to around 100 degrees toward central South Dakota. With humidity factored in, peak heat index values could reach 95 to 105 degrees, with locally higher values possible through portions of the Missouri River Valley if humidity levels remain high enough. Those with outdoor plans should take care to prevent heat illness, drinking plenty of water and spending time in air-conditioned places when possible.