One of the main challenges of forecast verification for health is the availability and quality of data. Health data can be scarce, incomplete, inconsistent, or delayed, making it difficult to obtain and compare the observed values with the predicted ones. Moreover, health data can be affected by measurement errors, reporting biases, and definitional issues, which can introduce noise and variability in the data. Another challenge is the choice and interpretation of verification metrics. There are many different ways to measure the accuracy, skill, and value of forecasts, such as mean absolute error, root mean square error, correlation, reliability, resolution, and sharpness. However, these metrics can have different meanings and implications depending on the context, scale, and purpose of the forecasts. For example, a forecast that is accurate at the national level may not be useful at the local level, or a forecast that is reliable in the short term may not be skillful in the long term.