Unusualy and Serious Heatwave

Description: Hotspots in this category illustrate notably warm periods or heat waves within the last few years. Candidate events were initially gathered from news reports and climate bulletins. We then looked at National Climatic Data Center and NASA/GISS websites to obtain the actual temperature records for the city or region to: a) verify the occurrence of the heat wave or warm period; and b) place it in the context of the longer-term temperature record. We avoided using one-day records because of the inherent probability that a maximum temperature record could be broken on any given day due to internal climate variability. Only those events that were notable either in duration or geographic extent were included. Whenever possible, periods at least as long as a month (e.g., hottest March ever on record) were chosen. We also included only those locations that fall within a region that showed a warming trend over the last century, as reported in Annex A of the IPCC's Regional Impacts of Climate Change (1998).