The degree to which the timing, duration and magnitude of local influenza virus epidemics is dependent on climate factors is poorly understood . Further, a host of non-climate confounders are likely to influence the incidence of seasonal influenza . This poses a number of challenges for making reliable climate-based epidemiological forecasts for influenza . Although no association between anomalous climate conditions and influenza have been reported in some locations , generally, low winter temperatures and humidity in temperate regions and periods of high humidity and precipitation in the tropical and subtropical regions have been linked to outbreaks of influenza . However, the climate sensitivity of influenza may be more complex than this, with both high and low humidity; the amount and intensity of precipitation; solar activity and/or sunshine; and latitude also being important . Moreover, the shape of the climate variable influenza relationship may be conditioned on influenza type . Further, distinct periods of weather variability characterised by rapid inter- daily changes in temperature may act as precursors to influenza epidemics as has been demonstrated for the marked 2017-2018
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report