Decoding Weather Fingerprints of Upper Respiratory Pathogens: A One-year Observational Study in Northern Greece.

Respiratory infections demonstrate characteristic seasonal variations influenced by environmental factors; however, the specific meteorological determinants for individual pathogens remain insufficiently defined. This retrospective study investigated associations between weather parameters and the prevalence of upper respiratory pathogens in northern Greece from December 2023 to November 2024. Nasopharyngeal specimens collected from patients at AHEPA University Hospital of Thessaloniki with suspected infections were analyzed using multiplex polymerase chain reaction (PCR). Meteorological data were incorporated through a novel timeweighted approach that aligned weather data with pathogen-specific incubation periods. Among 1,754 samples analyzed, winter exhibited the highest positivity rate. Distinct seasonal and meteorological relationships were identified across pathogens. Influenza A was associated with colder and more humid conditions, Adenovirus predominated in warmer periods, and other viruses displayed year-round or seasonally limited circulation. Distinct correlation profiles were also observed, including variations in temperature-humidity relationships among specific pathogens. These findings reveal pathogen-specific meteorological signatures extending beyond conventional seasonality and highlight the utility of time-weighted environmental modeling for improving predictive surveillance and public health preparedness.