Norovirus Outbreak 2026: Is It Going Around? CDC Data

As of mid-October 2026, norovirus activity in the United States is at normal early-season levels, with the yearly surge still ahead. The Centers for Disease Control and Prevention (CDC) counted 27 norovirus outbreaks in its 12 NoroSTAT sentinel states from August 1 through September 4, 2026, compared with 29 in the same weeks a year earlier, and described the total as within the usual range for 2012 to 2026. Outbreaks typically climb from November, peak between December and March, and fade by April.

This page tracks what the federal data show, what happened in the past two seasons, where outbreaks occur, the 2026 cruise ship and oyster alerts, and how to check activity where you live. Figures were checked on October 14, 2026, and each is labeled with its source date. For symptoms and care, see the main norovirus symptoms guide.

Is norovirus going around right now?

Some norovirus circulates all year, so the honest answer is always "a little." The better question is whether it is unusually active. Here is the most recent federal and wastewater picture.

Indicator	Latest reading	Data date	What it means
CDC NoroSTAT outbreaks, 12 states	27 outbreaks, August 1 to September 4, 2026 (29 in the same period of 2025)	Page updated September 17, 2026	Normal for late summer; within the middle 50 percent of past seasons
CDC CaliciNet strain typing	GII.4 Sydney 74 of 160 typed outbreaks (46 percent); GII.17 28 of 160 (18 percent), September 1, 2025 to September 30, 2026	Page updated October 9, 2026	The long-dominant GII.4 strain is back on top after GII.17's surge in 2024-25
WastewaterSCAN national norovirus level	"Medium," with a downward trend over the previous 21 days	Dashboard viewed October 14, 2026	Typical for early fall; this had been "high" in late May 2026
CDC cruise ship outbreak list	9 gastrointestinal outbreaks posted for 2026, 5 confirmed as norovirus; none posted after July	Page updated July 23, 2026	For comparison, 23 were posted for all of 2025

NoroSTAT is updated monthly, so a newer count may be posted shortly after this page's check date. The CDC also tracks the share of laboratory norovirus tests that come back positive through its NREVSS system, but that dashboard does not publish values in a form we could read and verify, so we have left it out rather than quote a number secondhand.

When is norovirus season?

Norovirus outbreaks occur throughout the year but are most common from November to April, according to the CDC. In the NoroSTAT record going back to 2012, the busiest weeks have fallen in January. About 2,500 norovirus outbreaks are reported in the United States each year, and the virus causes an estimated 19 to 21 million illnesses, 109,000 hospitalizations, and 900 deaths annually, the deaths mostly among adults 65 and older.

Search interest follows the same curve. Over the past year, Americans searched Google for "norovirus symptoms" most in December 2025, at more than twice the monthly average. The winter holidays combine everything the virus needs: crowds indoors, shared food, travel, and a lot of people cooking for others.

The last two seasons: an unusually large surge, then a return to normal

Seasonal year (August to July)	Outbreaks reported by NoroSTAT states	How CDC described it	Dominant strain
2023-24	1,449 (through early July)	Comparison year	Mixed; GII.17 34 percent, GII.4 28 percent
2024-25	2,650	Above the range of previous seasons	GII.17, about 75 percent of typed outbreaks
2025-26	1,392	Within the middle 50 percent of past seasons	GII.4 Sydney, 46 percent
2026-27 so far	27 (August 1 to September 4)	Within the middle 50 percent	Too early to say

The set of participating states changed slightly between seasons, so the totals are a guide to scale rather than an exact like-for-like comparison.

The 2024-25 winter was the outlier. The season started early, in October 2024, peaked in January 2025, and produced nearly twice the usual number of reported outbreaks. CDC scientists traced it to a strain called GII.17, which went from under 10 percent of typed outbreaks in 2022-23 to 75 percent in 2024-25, displacing GII.4 Sydney, the strain that had led for more than a decade. When a new strain takes over, fewer people have immunity to it, and the CDC notes that such years can bring 50 percent more norovirus illness.

The following season, 2025-26, was close to ordinary: 1,392 outbreaks, roughly half the previous year's count. GII.17 receded and GII.4 Sydney returned to the top spot in CDC's typing data.

Is there a new norovirus strain in 2026?

No new strain has been identified by the CDC. The strains circulating in 2026 are familiar ones. GII.17 was the newcomer of 2024-25 and has since declined. The symptoms are the same whichever strain is involved: sudden vomiting, watery diarrhea, nausea, and stomach cramps for one to three days. What changes with a new strain is how many people get sick, not how sick each person gets.

Where norovirus outbreaks happen

An outbreak is two or more similar illnesses from a common exposure. According to the CDC:

• Long-term care facilities. Over half of all reported norovirus outbreaks in the United States occur in nursing homes and similar facilities, where residents share space and staff and are more likely to become seriously ill.
• Restaurants and catered events. About half of all outbreaks of food-related illness are caused by norovirus, and most of those start in food service settings, usually from an infected worker handling ready-to-eat food.
• Schools, childcare centers, and colleges. Close contact and shared bathrooms, cafeterias, and dorms make these frequent sites.
• Cruise ships. Norovirus causes more than 90 percent of diarrheal disease outbreaks on cruise ships, yet ship outbreaks account for only about 1 percent of all reported norovirus outbreaks.

Most outbreaks spread person to person rather than through food. The mechanics are covered in how norovirus spreads and how long you are contagious.

Norovirus on cruise ships in 2026

Cruise ship outbreaks draw attention because ships must report them. The CDC's Vessel Sanitation Program posts an outbreak when a ship on an itinerary that includes U.S. and foreign ports has 3 percent or more of passengers or crew reporting gastrointestinal illness to the medical center. Through its July 23, 2026 update, the CDC had posted nine outbreaks for the year. Five were confirmed as norovirus:

Ship (cruise line)	Voyage dates	Passengers ill	Crew ill
Star Princess (Princess Cruises)	March 7 to 14, 2026	141 of 4,307 (3.3%)	52 of 1,561 (3.3%)
Caribbean Princess (Princess Cruises)	April 28 to May 11, 2026	145 of 3,116 (4.7%)	15 of 1,131 (1.3%)
National Geographic Sea Bird (Lindblad Expeditions)	May 26 to 31, 2026	9 of 66 (13.6%)	3 of 24 (12.5%)
National Geographic Sea Bird (Lindblad Expeditions)	June 25 to 30, 2026	19 of 68 (28%)	2 of 27 (7.4%)
Ruby Princess (Princess Cruises)	June 12 to July 2, 2026	107 of 3,032 (3.5%)	25 of 1,144 (2.2%)

Counts are CDC totals for the entire voyage; not everyone was sick at once. The other four posted outbreaks were two caused by E. coli (Seven Seas Mariner in January and Oceania Insignia in April) and two of undetermined cause on National Geographic Sea Bird in July.

For comparison, the Vessel Sanitation Program's tables for earlier years list 23 posted outbreaks in 2025 (18 with norovirus as the cause), 18 in 2024 (15 norovirus), and 14 in 2023 (13 norovirus), as those pages stood on October 14, 2026.

If you are booked on a cruise

• Keep the risk in proportion. More than 20 million passengers sail from North American ports each year. In CDC surveillance covering 2006 to 2019, the rate of gastrointestinal illness among passengers fell from 32.5 to 16.9 cases per 100,000 travel days.
• Check the ship. Ships under CDC jurisdiction are inspected unannounced, generally twice a year, and scored on a 100-point scale; 86 or higher is satisfactory. Scores are searchable in the CDC's inspection database.
• Wash hands with soap and water often, especially after using the toilet and before eating. Sanitizer dispensers at the buffet are a supplement, not a replacement.
• If you see someone get sick, leave the area and tell the crew.
• If you get sick, call the medical center. Under CDC standards, passengers with symptoms are asked to stay in their cabin until at least 24 hours after symptoms resolve. Reporting helps the ship contain the outbreak.
• Do not board sick. Check the cancellation policy when you book and consider trip insurance that covers illness, as the CDC's travel guidance suggests.
• Pack oral rehydration packets and any regular medicines in your carry-on.

Oysters and other food alerts in 2026

Raw oysters are the food most often tied to norovirus alerts, because oysters filter the water they grow in and are usually eaten raw. The Food and Drug Administration (FDA) issued three norovirus-related shellfish advisories in the first four months of 2026, and none between then and our check date:

FDA advisory date	Product	Harvest dates	States that received product
February 2026 (updated February 18)	Certain oysters from British Columbia, Canada, harvest area BC 17-20 (Stellar Bay Shellfish)	December 22, 2025 to February 4, 2026	CA, CO, FL, HI, IL, MD, NV, NY, PA, WA
March 9, 2026	Certain raw oysters and Manila clams from Drayton Harbor, Washington	February 13 to March 3, 2026	Oysters: WA. Clams: AZ, CA, FL, GA, IL, NV, NY, OR, WA
April 17, 2026	Recalled shellfish from a portion of Hammersley Inlet, Washington	March 22 to April 9, 2026	CA, OR, TX, WA

Those products are long past their shelf life; the list shows the pattern rather than a current risk. Shellfish advisories cluster in winter and early spring, so expect new ones from December onward. To lower your own risk, the CDC advises cooking oysters and other shellfish to an internal temperature of at least 145°F and warns that quick steaming does not heat them enough to kill the virus.

Is there a norovirus outbreak near me?

There is no national, county-level norovirus map. Norovirus is not a nationally notifiable disease for individual cases; only outbreaks are reported, and CDC's detailed counts come from a limited set of states. To get a local read:

1. Wastewater data. WastewaterSCAN, a program based at Stanford and Emory universities, publishes norovirus levels for participating sewage treatment plants, with national and regional summaries. It is the closest thing to a real-time local signal, though it covers only some communities.
2. Your state or county health department. Many post outbreak notices, restaurant closures, or seasonal gastrointestinal illness reports.
3. CDC NoroSTAT. Monthly outbreak counts from Colorado, Michigan, Minnesota, Nebraska, New Hampshire, North Carolina, Ohio, Oregon, South Carolina, Tennessee, Virginia, and Wisconsin.
4. CDC CaliciNet. A state-by-state count of laboratory-confirmed outbreaks, useful for seeing which strains are circulating.
5. School, daycare, and nursing home notices. These institutions usually tell families when a cluster of vomiting and diarrhea is under way, and they are often the earliest warning.

Maps on news sites and social media labeled "norovirus outbreak map" are typically built from the same NoroSTAT or wastewater data, sometimes months old. Check the date.

What to do when norovirus is going around

• Wash hands with soap and water for 20 seconds before eating and after using the bathroom. Hand sanitizer does not work well against norovirus.
• Stay home for 48 hours after vomiting or diarrhea stops, and keep sick children home for the same period.
• Do not prepare food for others while sick or for two days afterward. If you were due to host, hand the cooking to someone else; our Friendsgiving ideas can help a stand-in plan the meal.
• Keep unscented household bleach on hand; most everyday cleaning sprays and wipes are not effective. Mixing instructions are in how to kill norovirus.
• Stock oral rehydration solution before you need it. See norovirus treatment.
• Be especially careful around babies, adults over 65, pregnant women, and people with weakened immune systems.

There is no vaccine yet. The most advanced candidate is still in a Phase 3 trial; the details are in norovirus vaccine status.

When to get medical help

Most people recover at home within three days. Call a doctor if an adult has diarrhea for more than two days, cannot keep liquids down, has blood in the stool, a fever above 102°F, or signs of dehydration such as very little urine, a dry mouth, and dizziness when standing. Call promptly for any infant with symptoms. Call 911 for confusion, fainting, or a person who is difficult to wake.