Don’t swim in Northern California rivers, officials warn. How cold and fast is the water?

It is still too cold to swim in Northern California rivers, officials warned Thursday.

Temperatures are in the 90s in Sacramento — but don’t give into the temptation to take a dip in local waterways. The record Sierra snowpack is melting, causing fast and cold currents longer than even regulars are used to.

“The American River is flowing very fast this weekend, and we want residents to be aware of just how dangerous it can be,” said Liz Bellas, director of regional parks, in a Sacramento County news release Thursday.

“The flows are so swift that the rafting companies along the river aren’t renting out equipment this weekend – it’s just too dangerous.”

Water flowing out of the Nimbus Dam into the American River is anticipated to be flowing “six times higher” than normal for the summer months at 12,000 cubic feet per second, the news release stated.

Not only are rivers flowing fast, the water is cold, too.

How cold is the river water?

“Even though the air temperature feels really warm, the water is still running really cold and really fast from the snowmelt,” said Katrina Hand, a National Weather Service meteorologist.

Even for an experienced swimmer, cold water temperatures can create difficult conditions, Hand warned. Taking a plunge into cold water can be a shock to the body, and in some cases can become deadly.

The North Fork American River near Auburn warmed up only to 53 degrees Wednesday, according to data from the U.S. Geological Survey. It dipped as low as 47 degrees on May 3, 5, 6 and 7.

The American River near Fair Oaks in Sacramento County was measured at between 55 degrees and 56 degrees most of the past week. County officials in Thursday’s news release said the river is usually warmer than 60 degrees this time of year.

It looks like cold river temperatures will be similar during the Memorial Day holiday, but it’s still too soon to tell, Hand said.

County parks officials have closed the Howe Avenue river access point due to a high river level and fast flow. Popular Rancho Cordova-based American River Raft Rentals has temporarily stopped its rental operations due to high water level and flow, according to its website.

Two swimmers missing in foothills

Particularly dangerous is the American River, where Placer County officials say at least two people are missing and presumed drowned, in separate incidents during two of the past three weekends.

Deputies, fire personnel and other emergency responders launched two water search operations on the American River, one the evening of April 29 and the other this past Sunday afternoon, the Placer County Sheriff’s Office said in social media posts this month.

In the first incident, a group of friends from Sacramento and Placer counties called 911 to report that one person in their group had been swept away in the river around 7:45 p.m.

In the more recent incident, a Bay Area man recreating by Yankee Jims Bridge near Foresthill jumped into the North Fork American River and was also swept away by the water, Sheriff’s Office spokeswoman Angela Musallam confirmed.

Both people are still missing, the Sheriff’s Office said Thursday morning.

“Please don’t become the next victim,” sheriff’s officials wrote in a Facebook post.

Searches for each missing person have been scaled down, ongoing on a “limited but continuous” basis, according to the social media posts and Musallam.

South Yuba River also dangerous, officials say

Another popular weekend river destination within reasonable driving distance of Sacramento, the South Yuba River, is raging this spring.

A 17-year-old kayaker died April 19 on the South Yuba River, near the Bridgeport Crossing, according to a news release from the Nevada County Consolidated Fire District.

As with the American River, rugged terrain near the South Yuba makes it difficult for first responders to access those in need of immediate medical attention. After delays due to that terrain, arriving crews found the unresponsive teen on a river bank; he was pronounced dead at the scene, according to the news release.

Nevada County safety officials — who have started their own public awareness campaign titled “Stay Out, Stay Alive” — said this week that the South Yuba River has recently flowed up to 5,000 cubic feet per second.

That is astonishingly high: during August and September, the river often flows below 50 cfs, the Nevada County Office of Emergency Services said in a Facebook post.

Nevada County fire officials in last month’s news release said the teen who died was one of four experienced kayakers running the river together.

“This unfortunate event is an early reminder that our rivers are powerful, cold and relentless,” the department wrote.

‘It’ll grab a hold of you, and you’ll be gone’

In Placer County, dangerous conditions on the American River and rough terrain along its access points make water rescue operations difficult, sheriff’s officials wrote.

“This means we may not be able to enter the river immediately and will not be able to catch up to the individual, as they could have been swept too far downstream,” Thursday’s Facebook post continued.

Officials with the Placer County Sheriff’s Office, county Office of Emergency Services and Cal Fire’s Nevada-Yuba-Placer unit are collaborating on a public safety campaign this year called “Be River Wise.”

“Where you were playing last year in this river is not the same place you’ll be playing this year,” Sgt. Kevin Griffiths said in a video released by the agencies. “It’s moving very fast. It’ll grab a hold of you, and you’ll be gone.”

Below are risks associated you can take with plunging into a cold water river, according to the weather service:

• Body heat can be lost four times faster

• Cold shock can be just as severe for water temperatures ranging from 50 to 60 degrees to water temperatures at 35 degrees.

• Gasping for air and rapid breathing from the body immersing into the water can be triggered with water temperatures at 77 degrees.

• Wearing a life jacket can significantly increase survival rates

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