Prior to 1970, temperatures in Maryland and Virginia had been more or less flat over the course of the 20th century. But since that time, they have climbed sharply, warming about 2.5 degrees F - part of an abrupt steepening in the rise of nationwide winter temperatures.
Temperatures across the Lower 48 warmed at a rate of 0.61 degrees F per decade since 1970 says a report released by Climate Central today, a climate science and journalism organization. That’s a remarkable, nearly four-fold increase from the 0.13 degree per decade rate observed since 1912.
Of the Lower 48 states, the amount of warming in Maryland and Virginia since 1970 fell in the middle of the pack. The most warming focused across the northern tier with Minnesota, North Dakota, Wisconsin, Vermont and South Dakota - the top 5-fastest warming states.
The least warming tended to occur in the west and southwest. Washington, Colorado, Oregon, California and Nevada warmed least since 1970. No state cooled since 1970, although a bucket of 12 states, mostly in the Southeast cooled slightly over the course of the century (while warming markedly since 1970).
From 1970 to 2012, Maryland’s 0.74 degree per decade warming rate ranked 21st fastest in the country, and Virginia’s 0.58 degree per decade rate ranked 29th. (The decadal warming rates in Maryland and Virginia from 1912-2012 were 0.15 and 0.02, respectively).
Both Maryland’s and Virginia’s winter warming rates were higher than their annual warming rate of 0.51 degrees per decade and 0.46 degrees per decade, respectively.
Averaged over the country, nighttime warming (based on low temperatures) was typically more pronounced than daytime warming (based on high temperatures). In fact, the post-1970 nighttime warming rate was 30 percent higher than the overall (average) warming rate. But Virginia and Maryland were outliers in this respect, with Maryland’s nighttime warming about the same as its overall warming and Virginia’s nighttime warming a bit less (0.48 degrees per decade at night, versus 0.58 overall).
The nature of warming described in this report, highlighting the steepest warming in U.S. occurring in the northern states, at night, and during winter, is consistent with climate model projections.
In other climate news, NOAA today reported that the global temperature in January 2013, ranked as the 9th warmest on record, extending a streak of 335 consecutive months of above normal temperatures.