Heat advisory issued for D.C./Baltimore metro areas

Record heat maximum and minimum temperatures set between Saturday, June 4 and Tuesday, June 7. (HAMWeather.com)

Over the weekend, this sultry airmass brought historically hot temperatures to Houston, Texas which reached 105 degrees Sunday, its warmest June day in history. The Houston Chronicle reported new record highs were set there in five of the first six days in June. The Sunday records in both Houston and Galveston shattered old records by seven degrees.

The heat expanded north and east Monday. The Chicago Tribune reported highs reached at least 90 degrees in 28 states, with records set in 20 states. Locations that set new record highs include Gary, Indiana (93), Lincoln Park, Illinois (96), Fort Dodge, Iowa (104), Milwaukee, Wisconsin (94), Minneapolis, Minnesota (98) and New Orleans, Louisiana (95).

An excessive heat warnings is in effect for Minneapolis today, where highs in the upper 90s are expected. In Chicago, high are forecast to be in the mid-90s, potentially the hottest in nearly five years.

East Coast effects

With the heat wave heading east, heat advisories have been posted for the D.C. and Baltimore metropolitan areas Wednesday for heat indices as high as 105. In Baltimore city, a code red heat alert has been issued for both Wednesday and Thursday meaning the city will open 11 cooling centers.

In Philadelphia and surrounding areas, an excessive heat watch is in effect Wednesday afternoon through Thursday evening.

Here in Washington, D.C., we have already had three days at or above 95 degrees in 2011 and should tack on two more Wednesday and Thursday. Capital Weather Gang’s Ian Livingston indicates the long term average for 95+ degree days over an entire summer is 7 to 8, but that number has increased to 11 over the last 30 years.

Extreme heat the new normal by mid-century?

New research in the journal Climate Change Letters projects large increases in summer temperatures in the coming decades. Live Science quotes climate scientist Noah Diffenbaugh, an author of the study: “According to our projections, large areas of the globe are likely to warm up so quickly that, by the middle of this century, even the coolest summers will be hotter than the hottest summers of the past 50 years.”