Reply The heat wave extends beyond Baltimore — high temperatures will reach the 90s from Virginia to Maine, with heat indices into the triple digits, forecasters say. (Shutterstock) BALTIMORE, MD — Temperatures are expected to top 100 degrees on the heat index in the next few days, prompting Baltimore City Health Commissioner Dr. Letitia Dzirasa to issue a code red extreme heat advisory. The city's heat advisory is in effect from Tuesday, June 29, to Wednesday, June 30. It marks the first code red heat advisory of the season in Baltimore. Temperatures will be 96 degrees and feel like 101 degrees on the heat index, according to the National Weather Service forecast. The hottest point of the day will hit around 2 p.m. Tuesday.