Just one week ago today, we were beginning one of the greatest heat waves in most people's lifetime. The high temperature was 100 last Thursday. Then 100 and higher for four days in a row. Last Saturday the temperature briefly reached 106 (for 2 minutes not the required 5 minutes for "official" high) the official high was 105 As you can see this extreme temperature had only been reached 4 other times in Washington weather records. It sure was a week of brutal and dangerous heat for the thousands who were still without power and air conditioning after the fierce, Derecho of Friday, June 29 that caused widespread damage. But imagine what it was like in 1918 and1930, before air conditioning when Washington suffered an equal or even worseheat wave, without almost any place to cool off.From The Climatic Handbook U.S. Weather Bureau 1949
Back in 1930 the official temperature readings were made here in the "old" building of U.S. Weather Bureau building at 24th and M Street NW in Washington. Here is a view of the weather instruments on top of that building
The thermometer recording temperatures from 1907-1942 was62 feet above the ground. Not the height most of us look at our thermometer. Yes, the current "official" location for Washington weather records is next to the runway at National airport
but it is at about 3 feet above the ground. Even with the urban heat island and local heating at Regan National Airport our run of extreme heat sure does rival any recorded in Washington within the city and in the years when the thermometer was high above the city. Here are some of the observer notes from the "hot spell" of 1918
August 6: Intensely hot weather continued today with a maximum temperature of 105.5 which is the highest ever recorded at this station. Many prostrations from heat have been reported in the newspapers"
and from the record "hot spell" of July 18-22, 1930
"July 20, 1930: Extreme heat continued today, with maximum of 105.6 breaking all previous records for high temperature"
So our record last Saturday of 105 does put us in historic territory. Only a few times has Washington been that hot and maybe the temperature reading at 62 feet above the old buildings was higher than near the ground as we measure now. And how did folks cool off in the great heat of the 1900s . . . BAC-Before Air Conditioning? Well there was Rock Creek back then
Library of Congress More information on the history of weather observations in Washington, DC here.More in a blog by the Capital Weather Gang on the great heat of the 1930s. Are we done with temperatures 105 or higher this summer? Yes and if not, I'll see you wading in Rock Creek.