Figure 3
Mean daily temperatures (red line) for November to May in North Rhine-Westphalia. Virogenesis rate limit (blue line) and biting rate limit (green line). Source: Bundesministerium für Verkher, Bau und Stadtentwicklung. Klimadaten Deutschland. http://www.dwd.de/bvbw/appmanager/bvbw/dwdwwwDesktop?