Crime dropped significantly in the January to June 2014 period. (Robert Thomson/The Washington Post)

Serious crime in the Metro system was down significantly from January through June this year compared with the same six-month period in other years dating to 2010, the transit agency said.

A full report on crime in the subway and bus system in the first half of 2014 will be presented to the agency’s board of directors later this month, Metro spokesman Dan Stessel said. The report will show a drop in overall crime compared with similar periods in the recent past, mainly due to significant declines in robberies, bicycle thefts and snatch-thefts of mobile devices so far this year.

“While I recognize that one crime is one too many, today’s news is an opportunity to thank our officers for their hard work, as well as our customers for their awareness and vigilance,” Metro Police Chief Ronald Pavlik said in a statement.

He also attributed the decrease to data-driven officer deployment tactics, improvements in technology and better intelligence sharing with other law enforcement agencies.

The especially frigid weather early this year also appears to have been a significant contributor to the drop in crime. Besides apparently keeping some crooks in their homes, ice and snow in the mid-winter weeks led to the closings of schools, businesses and governments offices, reducing Metro ridership and lessening opportunities for crime.

In a category known as “Part 1 offenses,” crime in the transit system was down 31.6 percent in the first six months of this year compared with the same period last year, Metro said. The FBI defines Part 1 crimes as homicides, rapes, robberies, aggravated assaults, burglaries, larcenies, arsons and motor vehicle thefts.

Metro said 708 Part 1 crimes were reported in the transit system from January to June this year.

In comparison, for the same six-month period, there were 996 such crimes reported last year, 969 in 2012, 876 in 2011 and 1,105 in 2010. Specifically, Metro said, snatch-thefts of mobile devices dropped 49 percent, bicycle thefts declined 35 percent, and robberies were down 43 percent.