Colorado is in the midst of a record-breaking flu season. In the week ending Dec. 27, 2025, 831 people were hospitalized with influenza – the most since the state started tracking flu cases two decades ago. Hospitalizations eased the following week to 737 but still remain higher than prior years.
Colorado is among the top five states with the most flu activity in the country, with doctor’s visits for flu-like illness at a 30-year record high, according to the Centers for Disease Control and Prevention’s weekly influenza surveillance report.
