 The overnight forecast from news radio WJPF calls for clear skies with a low of 64. The forecast is brought to you by the SIU Credit Union, where members can earn double reward points on select purchases. Learn how at SIUCU.org. The new day, mostly sunny with a high of 89. Hot on Saturday with a high of 94. Heat index values near 110. Partly sunny skies, a 30% chance of showers, possibly afternoon thunderstorms. Sunshine on Sunday with a high of 85.