Top 20 Rainiest Cities and Towns in Maryland

Average annual measures give you an idea of what rain you can expect every year. We’ve also reviewed NOAA’s National Centers for Environmental Information’s Storm Events Database. We set the range for Nov. 30, 2015, to Nov. 30, 2020, reviewing the heavy rain events recorded during those five years.

Here are the top 20 cities ranked by rainfall amount. The numbers are the amount of rain recorded for a single storm. We’ve left out cities that registered several times on the list, showing only their highest total.

You can tell that the heavy rainfall of Sept. 28, 2016, from severe thunderstorms was a big event for Maryland. The top three-ranked cities are easily above the rest of the rankings, given the rainfall that day. That same storm hit Washington, D.C., as well.

The average annual rainfall in Baltimore is 42.9 inches. We’ve also taken a peek at Washington, D.C., which is near our office in Manassas, and seen that they have an average rainfall of 42.7 inches.

The lists above show that Maryland has plenty of annual precipitation, along with a fair number of heavy rainfall events from storms to just plain downpours. Given that climate, it’s critical to make sure your home is protected.

Here are our recommendations.

• Install and maintain gutters and downspouts. These are absolutely essential to control the water that runs off your roof. Make sure they are sized correctly by reviewing our article Calculating the Importance of Gutters and Drainage. Then remove leaves and clear obstructions as well as repair any damage on a regular basis.
• Install downspout extensions. Once the water is flowing into your gutters and rapidly through the downspouts, it’s no good if it just pools up around your foundation, seeping into the ground, and searching for ways to enter your basement or crawl space. Downspout extensions can move the water further away from your foundation before it hits the ground.
• Practice proper landscaping. Once the water emerges from the downspout extensions, it needs to keep moving. Grading the soil around your home to help the water move away is the best approach. That helps alleviate any buildup of water around your basement or crawl space.
• Waterproof your basement or crawl space. Even with all that, water is going to seep into the soil and form around the walls of your basement or crawl space. Inspect the walls closely, both inside and outside, for cracks as well as any openings for pipes and drain lines. Then fix them. Also, install a drainage system and sump pump with a backup battery to collect and remove leaks before they become problems.

Those are good starting points for protecting your home.

We also recommend that you consult the professionals at JES Foundation Repair for a free inspection and repair estimate to identify any issues with your basement or crawl space that need attention in preparation for heavy rains.