Observed Climatic Trends

Long-term Maryland temperatures since 1895 were slightly cooler in the late 1800s, followed by warming through the 1950s, and then cooling into the late 1960s. Since the late 1960s, temperatures have warmed steadily through the current portion of 2018. Overall there is a warming trend from the late 1800s. This trend of increasing temperatures is not uniform and changes in magnitude, but not sign, depending on the time of year. The following figures were generated using data from NOAA National Centers for Environmental information, Climate at a Glance: Statewide Time Series product.The scatter plots are the averaged annual values with a 5 year moving average (MA) was included to smooth out some of the year-to-year variability in the records. The bar plots indicated the observed trend in monthly data. Scatter plots for each month can be scrolled through as well. The monthly plots have an interpolated linear regression and 95% confidence interval about the regression plotted as well.

Maximum Temperature

Maryland max temperature

Average Temperature

Maryland avg temperature

Minimum Temperature

Maryland avg temperature
Maryland max temperature trends
Maryland avg temperature trends
Maryland avg temperature trends

Maryland precipitation was slightly below the 1895 to 2018 average between 1895 and 1970, with post 1970 becoming slightly wetter than the average with an overall increase in precipitation. However, there are considerable year to year and decade to decade variations. The trend of increasing precipitation is not uniformly distributed over the course of a year as show below.


Maryland precipitation trends

Monthly Time Series

Last revised 02 July 2018