SUMMARYThe incidence of dengue infection, a vector-borne disease transmitted by the mosquito Aedes aegypti, shows clear dependence on seasonal variation. Based on the quantification method that furnishes the size of the A. aegypti population in terms of the estimated entomological parameters for different temperatures, we assessed the risk of dengue outbreaks. The persistence and severity of epidemics can be assessed by the basic reproduction number R₀, which varies with temperature. The expression for R₀ obtained from ‘true’ and ‘pseudo’ mass action laws for dengue infection is discussed.