The National Weather Service has replaced the heat advisory for Douglas County with an excessive heat warning until 8 p.m. Monday.

Temperatures are expected to remain in the middle 90s, with heat index readings between 105 and 110 degrees. Relief from the humid airmass is not expected until after Tuesday.

An excessive heat warning is issued when there is a heat index of at least 105 degrees for more than 3 hours per day for 2 consecutive days, or a heat index of more than 115 degrees for any period of time. A heat advisory is issued when the heat index is at least 105 degrees but less than 115 degrees for less than 3 hours per day, or when nighttime lows are above 80 degrees for two consecutive days.

Prolonged exposure to heat and humidity of this magnitude can cause dehydration, heat exhaustion and heat stroke. If you plan to be outside, avoid strenuous activity and drink plenty of water to avoid dehydration. Wear light-weight, light-colored and loose-fitting clothing. Wear sunscreen to avoid sunburn.

Counties under the NWS excessive heat warning include:

• Allen
• Anderson
• Bourbon
• Butler
• Chase
• Chautauqua
• Cherokee
• Coffey
• Cowley
• Crawford
• Douglas
• Elk
• Franklin
• Greenwood
• Jefferson
• Johnson
• Labette
• Leavenworth
• Linn
• Lyon
• Miami
• Montgomery
• Neosho
• Osage
• Shawnee
• Wabaunsee
• Wilson
• Woodson
• Wyandotte

Counties that remain under the heat advisory until 7 p.m. Sunday are:

• Atchison
• Clay
• Cloud
• Dickinson
• Doniphan
• Geary
• Jackson
• Marshall
• Morris
• Pottawatomie
• Republic
• Riley
• Washington