By far, 2018 was Baltimore's wettest year on record. Just how wet was it?
Precipitation at Baltimore-Washington International Thurgood Marshall Airport surpassed the previous record, 62.66 inches in 2003, by Nov. 15. And in the six weeks that followed, more than 9 inches of rain fell — the same amount that falls in the final three months of an average year.
For the year, precipitation at BWI, the region's point of record, totaled 71.82 inches.
Baltimore's weather record book goes back to 1871.
Here's a breakdown of the historic year:
145 rainy (and snowy days)
There was at least one-hundredth of an inch of rain at BWI on about 4 out of every 10 days. That adds up to 12 or 13 rainy days every month, on average — but in September, it rained on six out of every 10 days.
Climate data websites suggest Baltimore normally gets about 110 rainy days in a year.
Seven records within a record year
There were six daily rainfall records set, five of them during what was an unusually wet summer:
» December finished the year as the seventh-wettest, with 6.54 inches of rain.
The region also unofficially set records for the most rain within any 14-day, 60-day, 90-day, 120-day, 180-day and 365-day period. There was more than 48 inches of precipitation in the 180 days ending Nov. 9, for example — about 6 inches more than Baltimore usually gets in a year.
There had been more than 66 inches of rain in the 365 days ending Nov. 26, just barely surpassing the 365-day period that ended Aug. 4, 1889.
Three flooding deaths
Floodwaters were so dangerous, they caused three deaths in two separate incidents this year.
Sgt. Eddison "Eddie" A. Hermond, 39, was swept away as he rushed to help a shop owner in Ellicott City on May 27, and his body was found days later. A devastating deluge struck the old mill town for the second time in two years.
On Sunday, May 27, thunderstorms pounded the Baltimore region for hours. The storm morphed Old Ellicott City into a deadly flood zone. Here’s how it happened. (Baltimore Sun video)
2 feet above normal
Precipitation across most of Central Maryland ended up more than 2 feet above normal, according to National Weather Service models. Many areas received more than 150 percent of normal rainfall, and in some areas, including Southwest Baltimore and areas around Frederick, it's more than 200 percent. More than 80 inches of precipitation fell in Catonsville and Thurmont, according to the National Weather Service.
On average, about 42 inches of precipitation falls at BWI in a full year.
Two tropical systems
Some of the rainfall came from brushes with the remnants of Hurricane Florence in September and Hurricane Michael in October.
But what meteorologists found remarkable about the year of wet weather is that none of it was the product of a direct hit with a tropical system, unlike many of Baltimore's other wettest years on record.
Much of the rain was instead the result of an unusual and persistently wet weather pattern that dominated for much of the summer.
1 inch of rainfall — in 10 minutes
It's impossible to know when and where the most intense burst of rainfall fell — but if Ellicott City's flooding is any indication, there were moments of extreme precipitation around the state.
As torrential downpours hovered over the historic mill town May 27, 0.96 inches of rain fell in a 10-minute span, from 4:11 p.m. to 4:21 p.m. Almost 2 inches fell within a 30-minute stretch, and nearly 3 inches within an hour. Ellicott City saw 6.56 inches of rain in a three-hour span that afternoon.