Record Heat Surpasses Record Cold

Although winter will make a return tonight with colder, more seasonal temperatures this weekend, DC Area residents enjoyed this week’s record-setting warmth.  In fact, Washingtonians had high temperatures of at least 55° on six consecutive days this week (February 3 – 8).  That’s been a nice change for all but those who want snowfall.

The Nation’s Capital set a record high of 74° on February 5, which was almost 30° above the average high for the date of 45°.  It was also the third consecutive year that Washingtonians experienced their first 70° day of the year on or prior to February 15.  NOAA released a report this week that said 2018 was the fourth warmest year on record globally.  To add to that, “Nine of the 10 warmest years have occurred since 2005, with the last five years comprising the five hottest,” according to NOAA.

Washington, D.C., has had a total of 85 record high temperatures over the last 20 years (1999-2018).  That’s compared to only five record low temperatures.  Over the same time period, the Nation’s Capital had 184 record high/low temperatures.  That means the coolest temperature of the day was significantly warmer than the average low temperature.  At the same time, DC had only 20 record low high temperatures (daily high temperatures that were much cooler than average) for a rough nine to one ratio.

At Dulles Airport, where the urban heat island effect has less of an impact, there was a similar trend.  For example, Dulles had 188 record high temperatures in the last 20 years compared to 50 record low temperatures.  Dulles also had 310 record high low temperatures compared to 144 record low high temperatures.

These global temperature trends coincide with an increased amount of urbanization and development, as well as an increase in greenhouse gas emissions.  Locally, the much higher frequency of record heat compared to record cold can also be attributed to an increasing urban heat island effect.  The population density is much greater in the DC Metro Area today compared to the 1980s and 1990s.  That also means more people were able to enjoy the spring-like temperatures that occurred this week.