CHICAGO (NewsNation) — As the United States reels over the massacre of 19 children and two teachers at a Uvalde, Texas elementary school, multiple mass shootings have happened elsewhere across the nation.

According to the Gun Violence Archive (GVA), 20 mass shootings have happened since Uvalde.

The GVA defines a mass shooting as a single incident where four or more people, not including the gunman, are either shot or killed.

Authorities say a gunman carrying a rifle and handgun killed four people Wednesday in a medical building on the campus of Saint Francis Health System in Tulsa, Oklahoma.

That shooting was the latest in a series of deadly mass shootings across the United States in recent weeks. May 26 was the only day within the last week where a mass shooting did not happen, according to the GVA.

Over the Memorial Day weekend, several mass shootings happened in rural and urban areas. Single-death incidents still accounted for most gun fatalities.

Gunfire erupted in the predawn hours of Sunday at a festival in Taft, Oklahoma, sending hundreds of revelers scattering and customers inside the nearby Boots Café diving for cover. Eight people ages 9 to 56 were shot, and one of them died.

Six children ages 13 to 15 were wounded Saturday night in a touristy quarter of Chattanooga, Tennessee. Two groups got into an altercation, and two people in one of them pulled guns and started shooting.

Ten people were wounded and three law enforcement officers were injured in a shooting incident at a Memorial Day nighttime street gathering in Charleston, South Carolina.

And at a club and liquor store in Benton Harbor in southwestern Michigan, a 19-year-old man was killed, and six other people were wounded after gunfire rang out among a crowd around 2:30 a.m. Monday. Police found multiple shell casings of various calibers.

Such occurrences have become so regular that news of them is likely to fade fast.

Single-fatality shootings also rocked families and communities.

In Arkansas, a 7-year-old girl was killed Saturday in a busy area near the Little Rock Zoo, in what police described as “an isolated event involving acquaintances.”

And on Chicago’s South Side, the body of a young man slain at an outdoor birthday party lay on the sidewalk early Sunday, covered by a white sheet. His mother stood nearby, crying.

Overall, Chicago recorded 32 gunfire incidents over the weekend in which 47 people were shot and nine died.

It’s long been a rule of thumb in northern cities that hot weather means more violence. Temperatures in Detroit and Chicago were in the 80s — unseasonably warm — during the three-day weekend, bringing more people outside and increasing the chances of clashes, often between rival gangs. Alcohol at holiday parties can fuel personal beefs, some of which first fester online.