MARYLAND AT A GLANCE

WEATHER

[photo, Autumn leaves, Boonsboro, Maryland]


Autumn leaves, Boonsboro, Maryland, October 2019. Photo by Diane F. Evartt.

[photo, Sailboats, Back Creek, Annapolis, Maryland]
  • National Hurricane Center
  • National Weather Service
  • National Weather Service Forecast Office (Baltimore/Washington)

  • Earthquakes
  • Hurricanes
  • Hydrologic Indicators (rainfall, streamflow, groundwater, reservoirs)
  • Sunrise & Sunset
  • Temperature (average monthly)
  • Tornadoes
  • Maryland Winters
    • Sailboats, Back Creek, Annapolis, Maryland, October 2008. Photo by Diane F. Evartt.
    [photo, Murals on a sunny day, Wells St. at Hanover St., Baltimore, Maryland] Temperature. Average annual temperature: 55.1 degrees Fahrenheit. High temperatures occur in July, the warmest month, averaging in the mid to upper 80s. Low temperatures in January, the coldest month, average in the low to mid 20s.

    Since 1871, the mean temperature for Baltimore has been 54.6 degrees Fahrenheit, according to the State Climatologist Office. The highest recorded annual average temperature was 59.2 degrees in 1931, and the lowest was in 1904, at 52.6 degrees.

    Murals on a sunny day, Wells St. at Hanover St., Baltimore, Maryland, July 2003. Photo by Diane F. Evartt.

    [photo, Crabapple tree in bloom, Baltimore, Maryland] Affiliated with the Department of Atmospheric and Oceanic Science at the University of Maryland College Park, the State Climatologist Office is the State repository for climate information.

    Temperatures were recorded at Friendship Airport starting in 1950. Located just south of Baltimore City in Northern Anne Arundel County, the Airport was renamed Baltimore-Washington International (BWI) Airport in 1973, and BWI Thurgood Marshall Airport in 2005.

    Crabapple tree in bloom, Baltimore, Maryland, May 2014. Photo by Sarah A. Hanks.

    [photo, Annapolis waterfront, Spa Creek (near juncture with Severn River), Annapolis, Maryland] Precipitation. Average annual precipitation: 59 inches. Peaks in July and August when thunderstorms average once every five days.

    Since 1871, Baltimore's recorded precipitation has averaged 41.94 inches a year, with the highest amount falling in 2003, when 62.66 inches fell. The lowest precipitation recorded was in 1930, when only 21.55 inches fell throughout the year.

    Annapolis waterfront, Spa Creek (near juncture with Severn River), Annapolis, Maryland, May 2000. Photo by Diane F. Evartt.

    [photo, Snowman Goin' to the Beach, Glen Burnie, Maryland] Snow. Average seasonal snowfall: 20.6 inches. Ranges from 10 inches on the lower Eastern Shore to 110 inches in Garrett County. The most snowfall ever recorded in a single winter in Maryland was during the winter of 2009-10, when 262.5 inches of snow fell at Keysers Ridge in Garrett County.

    Summer Weather. In summer, the average temperature is 72.7 degrees Fahrenheit. Maryland summers vary from mild to hot, with greater levels of humidity in eastern and southern areas.


    Snowman "Goin' to the Beach", Glen Burnie, Maryland, January 2011. Photo by Diane F. Evartt.

    Winter Weather. Winter temperatures average 34.1 degrees. While the Eastern Shore and Southern Maryland remain cool, western counties experience colder weather, and more snow.

    Year round, weather in Maryland is fairly mild, though temperatures vary between areas of the State. Fluctuations in temperature can be attributed to elevation, and coastal area. One example is the temperature difference between Savage River Dam in Garrett County, and Royal Oak on the Eastern Shore. Located between the towns of Accident and Westernport, Savage River Dam is 1,495 feet above sea level. Near Easton in Talbot County, Royal Oak's average elevation is only ten feet above sea level. In January, Maryland’s coldest month, average temperature for the two locales differs noticeably. Royal Oak's mean temperature is 36.1 degrees Fahrenheit, while that for Savage River Dam averages 26.2 degrees. This discrepancy continues in July, the warmest month, when mean temperatures are 69.7 Fahrenheit for Savage River Dam, and 78.6 degrees for Royal Oak.

    [photo, Snow, Glen Burnie, Maryland] Maryland is classified as temperate of climate, that is, as being located between the Tropic of Cancer (23º 27' north latitude) and the Arctic Circle (66º 33' north latitude) in the Northern Hemisphere. Temperate climates are noted for four distinct seasons. The U.S. Department of Agriculture further divides the nation by climate zones for use in regards to plant hardiness. Across Maryland are five of these zones: 5b, 6a, 6b, 7a, 7b. Consequently, the average annual minimum temperature across the State can vary from -15 degrees in the mountains of Garrett County, to 10 degrees in southern Maryland or in Ocean City.

    Snow, Glen Burnie, Maryland, March 2018. Photo by Diane F. Evartt.

    [photo, Snow, Glen Burnie, Maryland] Duration of the freeze-free period averages 185 days, ranging from 130 days in Garrett County to 230 days in southern Maryland and the lower Eastern Shore.

    Maryland's Groundhog. Each Groundhog's Day, "Western Maryland Murray", a Cumberland groundhog or woodchuck, predicts how long winter will last in Maryland. On February 2, 2019, Western Maryland Murray, also known as "Mountain Maryland Murray", saw his shadow, predicting six more weeks of winter.

    Snow, Glen Burnie, Maryland, March 2018. Photo by Diane F. Evartt.

    Earthquakes. Seismically quiet compared to neighboring states, Maryland has experienced only 64 recorded earthquakes within its borders since 1758. In contrast, Pennsylvania recorded nearly 100 quakes (since 1724), and Virginia had more than 300 (since 1774). Most earthquakes are minor, and rate less than 3.0 on the Richter scale. This means that while they may be recorded and perceived, it is unlikely that they are felt at any distance from the epicenter. These lesser earthquakes occur at least once a year along the east coast.

    The strongest earthquake recorded in Maryland was a 3.7 that occurred on November 26, 1939, near Phoenix in Baltimore County. The strongest earthquake to hit the East Coast of the United States was on September 1, 1886, when a 7.3 struck Charleston, South Carolina.

    On August 23, 2011, an earthquake centered near Louisa, Virginia (northwest of Richmond) reached 5.8 on the Richter scale. The most powerful earthquake to hit the East Coast in almost 70 years, it was felt in Maryland and along most of the eastern seaboard, leading to the evacuation of numerous offices and buildings. Despite its strength, the earthquake caused only minimal damage, and no casualties.

    Hurricanes. Storm effects from hurricanes moving up the East Coast are felt in Maryland almost every year, most often in August and September. High winds, heavy rains, and sometimes flash floods accompany these storms. Nonetheless, never has a major hurricane (category 3 or higher) directly hit Maryland, and only rarely has a lesser hurricane directly hit the State. Since recordkeeping began in 1851, only two lesser hurricanes have directly hit Maryland: one in 1878, and the Chesapeake and Potomac hurricane in 1933.

    More recently on August 27 and 28, 2011, Hurricane Irene skirted the coast of the Delmarva Peninsula as a category 1 hurricane. Though the core of the storm did not make landfall in Maryland, hurricane force winds were felt in Somerset, Wicomico and Worcester counties, with tropical storm force winds reaching as far west as Frederick. High winds and heavy rains from the storm led to extensive flooding and power outages.

    Tornadoes. Historically, Maryland averages three reported tornadoes each year, most often occurring between May and July. The most powerful tornado recorded in Maryland occured on April 29, 2002, in Calvert and Charles counties. Briefly reaching F5 status, it covered more than 30 miles, and had winds in excess of 260 mph.

    Wildfires. On average, there are more than 5,000 wildfires per year in Maryland which burn several thousand acres. These fires are more likely to occur during the spring and fall months when the air is drier. While lightning causes some fires (about 4%), most are set either accidentally or intentionally by people.

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