A heat wave is a long period of extremely hot weather, which may be followed by high humidity. There is no definition of a heat wave that everyone agrees on; the term depends on the usual weather in the area. Temperatures that people from a hotter climate consider normal can be called a heat wave in a cooler area if they are outside the normal climate pattern for that area. The term is used on both common weather changes and to very hot spells which may occur only once a century.
- Meehl, George A.; Tebaldi, Claudia (August 13, 2004). "More Intense, More Frequent, and Longer Lasting Heat Waves in the 21st Century". Science 305 (5686). http://www.sciencemag.org/cgi/content/full/305/5686/994.
- Robinson, Peter J. (April 2001). "On the Definition of a Heat Wave". Journal of Applied Meteorology (American Meteorological Society) 40 (4): 762-775. http://ams.allenpress.com/amsonline/?request=get-abstract&doi=10.1175%2F1520-0450(2001)040%3C0762:OTDOAH%3E2.0.CO%3B2.