The *Respiratory Outlook* update for December provides the latest forecasts as we near the peak season for flu, COVID-19, and RSV. The [*Respiratory Outlook 2025/26*](https://www.metaculus.com/tournament/respiratory-outlook-25-26/) is a collaboration between the Centers for Disease Control and Prevention (CDC) and Metaculus. Metaculus Community forecasts are shared with the CDC and do not necessarily reflect CDC views.

**Compared with the** [**November edition**](https://www.metaculus.com/notebooks/40863/november-forecasts-for-respiratory-and-measles-this-season/)**, this month saw:**

* A significant increase in predicted measles cases for 2026 after recent off-season measles data showed high prevalence, with a median forecast of 1,396 cases, well above the [typical annual number of cases](https://www.cdc.gov/measles/data-research/index.html#:~:text=Skipped%20data%20table.-,Yearly%20measles%20cases,-as%20of%20December) over the last few decades.
* The probability of a High or Very High severity flu season saw a slight decrease to 28.2%.
* Forecasters have made small adjustments to their predictions for the magnitude and timing of the peak for flu, COVID-19, RSV, and their combined burden based on early data.

![](https://cdn.metaculus.com/user_uploaded/image_msqx1nc.png)

*Weekly hospitalization rates per 100,000 according to RESP-NET along with Metaculus forecasts for the peak hospitalization rate in the 2025-26 season and the associated timing. Diamonds reflect median forecasts for the magnitude and timing of the peak, vertical bars show 50% prediction intervals for the magnitude, and horizontal bars show 50% prediction intervals for the timing of the peak. Forecasts from last month (November 24) are shown with transparency.*

## [**Read the full report**](https://www.metaculus.com/files/Respiratory-Outlook-Update-December-2025)

## [**Share your forecasts**](https://www.metaculus.com/tournament/respiratory-outlook-25-26/)