What is required in the weather to achieve a "heat wave"?

Arpeggionist

A temperature of several degrees higher than normal for the season. Thus in winter in New York, where the temperatures normally hover around 35 Farenheit, if it were 45 Farenheit for a day or two, that would be a heat wave. But during the summer 45 Farenheit in the same place would be quite a cold streak. Jun 08 05, 12:08 PM

barker111

Actually it is a technical term that requires at least three days in a row all over 90 degrees. Using the National Weather Service (NWS) as its source: http://www.sema.state.mo.us/sh%20annex%20e.pdf Jun 08 05, 1:21 PM

gmackematix

The definition is dependent on the local climate. http://en.wikipedia.org/wiki/Heat_wave Jun 08 05, 5:44 PM

MrsAce

Barker, what you describe is a "hot wave". In 1900, A. T. Burrows more rigidly defined a “hot wave” as a spell of three or more days on each of which the maximum shade temperature reaches or exceeds 90°F. (Source: American Meteorological Society) http://amsglossary.allenpress.com/glossary/search?p=1&query=heat+wave Jun 09 05, 4:46 AM

nightowl4

A heat wave is a period of at least 5 days, when the temperature is above average for that time of year. http://en.wikipedia.org/wiki/Heat_wave#Definition_of_Heat_Wave Apr 02 07, 2:26 PM