An overwintering zone is first carried out (defined for mean January temperatures above 0C and annual rainfall above 500mm). Then critical annual temperature thresholds (9-10-11-12C) are depicted based on Kobayashi et al, 2002. The 11C isotherm (light red on the figure) has been shown to fit the observed distribution of the mosquito for Japan and the USA. The present period (1950-2009) is based on gridded observation data, while the future projections (2010-2050) are based on the regional climate model ensemble mean carried out within the ENSEMBLES project (SRESA1B) scenario. Trends are depicted as a 5 year running average is applied to the data. The RCMs outputs are mean bias corrected with respect to the observations.