In the latest incident on Monday, seven people were killed and one critically injured in two related shootings at agricultural facilities in a coastal community in northern California.
The shooting came less than 48 hours after a gunman killed 11 people at a Lunar New Year celebration near Los Angeles, California, on Saturday night.
Mass shootings are incidents in which four or more people are shot – excluding the attacker – in a single incident, according to the GVA.
Here is a timeline of mass shootings that have taken place across the US this month so far:
January 23
Chicago, Illinois (two killed, three injured)
Half Moon Bay, California (seven killed, one injured)
January 22
Robinsonville (Tunica Resorts), Mississippi (four injured)
Baton Rouge, Louisiana (12 injured)
Shreveport, Louisiana (eight injured)
January 21
Monterey Park, California (11 killed, nine injured)
January 17
Houston, Texas (four injured)
January 16
Fort Pierce, Florida (one killed, seven injured)
Goshen, California (six killed)
Sanford, Florida (one killed, five injured)
January 15
Rockford, Illinois (three killed, two injured)
Homestead, Florida (one killed, three injured)
Phoenix, Arizona (four injured)
Houston, Texas (one killed, four injured)
January 14
Saint Louis (Moline Acres), Missouri (four injured)
January 13
Cleveland, Ohio (four killed, one injured)
January 9
Philadelphia, Pennsylvania (three killed, four injured)
Minneapolis, Minnesota (four injured)
Denver, Colorado (four injured)
January 8
Minneapolis, Minnesota (four injured)
Albany, Georgia (four injured)
January 7
Huntsville, Alabama (two killed, nine injured)
High Point, North Carolina (five killed)
January 6
Dallas, Texas (three killed, two injured)
San Francisco, California (one killed, three injured)
January 5
New Orleans, Louisiana (two killed, three injured)
Miami Gardens, Florida (10 injured)
January 4
Cedar City (Enoch), Utah (eight killed)
Baltimore, Maryland (one killed, four injured)
Dumfries, Virginia (one killed, four injured)
January 3
Washington, DC (one killed, three injured)
New Orleans, Louisiana (five injured)
January 1
Columbus, Ohio (one killed, four injured)
Ocala, Florida (two killed, four injured)
Chicago, Illinois (one killed, three injured)
Miami Gardens, Florida (nine injured)
Durham, North Carolina (five injured)
Allentown, Pennsylvania (four injured)