A heat advisory will go into effect at 1 p.m. and last until 8 p.m. Friday.
The temperature was already 86 degrees by 11 a.m., with a heat index of 91.
Similar temperatures are expected over the weekend, although humidity values and heat indices will be slightly lower, according to the weather service.
There is a 20 percent chance of thunderstorms late tonight. The severe weather and heavy rain threats are low.
Tips on handling the heat:
• Those exposed to the high heat and humidity over a prolonged period will have an increased risk of heat-related illnesses. Cars may reach lethal temperatures in minutes. Never leave children or pets unattended in a vehicle, not even for a minute.
• Drink plenty of water. Avoid caffeinated, alcoholic and high sugar content beverages.
• Stay in an air-conditioned room. Stay out of the sun.
• Check up on neighbors, the elderly and pets.
• If you work outside, reschedule strenuous activities to early morning or late evening.
• Know the signs and symptoms of heat exhaustion and heat stroke.
• Wear light-colored, lightweight and loose-fitting clothing when possible.
• Schedule frequent rest breaks in shaded or air-conditioned environments.
• Move anyone overcome by heat to a cool and shaded location and seek help by calling 911 immediately.
• If you don’t have air-conditioning, look for an air-conditioned public library, recreation center, Salvation Army at 67th and State, a store or other public place.