Is the mild winter this year in the D.C. area a fluke or a sign that the local climate is changing? Since the D.C. area first began recording annual average precipitation and temperature in 1947, the average temperature has increased by 0.3⁰F per decade. From 1947 to 2014, the average temperature in the D.C. area has increased by 2⁰F. The average high temperature for January, February, and March of this year was 46⁰F, 49⁰F, and 59⁰F, respectively. These average values are higher when compared to the average high temperatures of 40⁰F, 44⁰F, and 54⁰F recorded for these three months, respectively, over the thirty-year period from 1982-2012. The average monthly precipitation for January, February, and March of this year compared to the same 30 year period is almost the same at approximately 3 inches per month.
Due to the warmer winters in Maryland, the local insect population has tripled over the past three years. Tick and flea eggs thrive in temperatures of 45⁰F or more, and mosquito eggs thrive at 55⁰F or more. Although there are 60 known mosquito species in Maryland, the number and types of species have evolved with the Asian Tiger being the most recent and most common mosquito species now found in Montgomery County. The Yellow Fever species has been less commonly found in this area in the past because their eggs don’t survive typical Maryland winters but this and other mosquito species may be increasing with the trend in rising temperatures.
The increase in tick and mosquito populations could negatively impact not only the local ecosystem but also public health. In May of 2018, the CDC stated that the number of tick-borne illnesses in the U.S. has doubled between 2004-2016 with the most common illness being Lyme disease. According to the director of the CDC’s Division of Vector-Borne Diseases, one cause of this large increase may be the warmer weather, which makes the season longer for which ticks are active. Another cause may be the growing deer population which acts as the host for some of the most common tick-borne illnesses. The CDC states that mosquito borne-illnesses have also increased for the same reasons, but those numbers are less reliable because of outbreaks such as Zika. Lastly, ticks can spread new illnesses by interacting with and transmitting germs from new animals to humans.
The director of the CDC states that accurately predicting how bad the upcoming tick season could be is difficult. However there are measures people can take in protecting themselves such as the following: dressing properly to cover skin when going outside, applying bug repellent containing ingredients known to prevent mosquitoes and ticks, and bug-proofing pets and yards.
Article by Shaunak Dua of Herbert Hoover Middle School
Image courtesy of Creative Commons