The CDC expects the 2025–2026 U.S. autumn and winter respiratory season to have a similar combined peak hospitalisation rate for COVID-19, influenza and RSV as last year, although multiple peaks and regional variations are possible. COVID-19 hospitalisations could increase if a new variant emerges, while influenza is expected to be moderate and RSV hospitalisations stable due to new immunisations for high-risk groups. Vaccination and preparedness remain key to managing hospital demand. 

Extreme heat and air pollution are also increasingly influential in shaping travel patterns, particularly in cities hosting major events, such as 2026 FIFA World Cup venues, where large crowds can exacerbate health risks. Travellers are more frequently considering local climate conditions, air quality indices and potential disruptions when planning trips, which can affect attendance, transportation choices and overall event experiences.

High-pollution regions are particularly concerning in countries such as India, Pakistan and China, where seasonal factors like slash and burn activities, industrial emissions and dust storms can drastically reduce air quality; seasonal bushfires in Australia and New Zealand also significantly affect air quality in otherwise less-polluted cities. These environmental conditions not only pose direct health risks, such as respiratory issues and heat-related illnesses, but also lead to temporary closures, flight delays and cancellations. As a result, travel companies, event organisers and public health authorities are increasingly integrating environmental monitoring and mitigation strategies into their planning to ensure traveller safety and maintain operational continuity.

Vector-borne diseases are expanding geographically due to climate change, with dengue, malaria and cholera posing heightened risks in Africa, Asia and Latin America. Ebola in the Democratic Republic of the Congo (DRC) and Marburg in Ethiopia remain significant concerns. La Niña weather patterns may further exacerbate disease outbreaks across multiple regions, underscoring the ongoing importance of disease monitoring and preparedness.