The heat was clearly most dominant in the middle of the 20th century with “secondary smaller max in recent decades. There is no evidence of an increasing trend.
The state record lows actually peaked in the 1960s and 1980s but were very low early and late in the record. Combined with the record high, this decade is unusually benign with an absence of extremes, not an increase. Fewer record lows with no corresponding increase of record highs actually is a benefit not a liability as it reduces need for heating (energy).
In summary, the increasing heat wave notion comes entirely from model forecasts, models which are failing.
HEAT WAVE MORBIDITY
The claim that warming increases morbidity rates is also a myth. Dr. Robert Mendelsohn, an environmental economist from Yale University argues that heat-stress deaths are caused by temperature variability and not warming. Those deaths grow in number not as climates warm but as the variability in climate increases. The deaths are greater in northern climates when sudden heat waves occur and were the populace has not adapted to heat. Excess deaths are greatest in metropolitan areas among the elderly and when the nighttime readings stay high (80F) or greater and the heat lasts more than a few days. After an event like that the populace adapts.
As Nico Stehr and Hans von Storch in an essay in 2005 noted: “Adaptation, by contrast, works. Precautionary and preventative measures are effective in preventing fatalities from heat, for example. While a tragedy occurred in Chicago in mid-July 1995, with more than 700 “heat deaths,” in the same summer the so-called “hot weather health warning watch system” saved the lives of about 300 people in the city of Philadelphia. The occurrence of extremely high temperatures in Philadelphia in 1993 and 1994 prompted the development of an efficient warning system and social networks that benefited the elderly and other persons at risk.
What does this mean? In reality, it was the isolation of elderly people in Chicago who did not know how to help themselves, or the poverty (and thus also: helplessness), which was much worse in this region ten years ago, that led to the high number of fatalities.”
A similar story can be said for the heat waves in Europe in 2003. The timing of the event (summer vacation where most families went to the oceans while mostly the elderly remained in homes without air conditioning) led to excess premature deaths. Subsequent hot days in more recent years have not brought the same results.
Indur Glokany in Death and Death Rates Due to Extreme Weather Events, in 2007 showed deaths from all extremes for 1979-2002. It showed death from extreme cold continues to exceed death from extreme heat.
Death Risk may be increased by policies that limit reliable traditional energy sources in favor of renewables such as wind power which increase the likelihood of brownouts and blackouts. It is during the normal heat waves, that energy demand is the greatest. Also during extremes of heat and cold, high pressure dominates, causing winds to be below the threshold for energy generation. This has already been shown in Texas, California and the UK (see link). This policy not the weather if implemented would put the population at enhanced risk.
Goklany, I.M.; Straja, S.R. 2000. U.S. death rates due to extreme heat and cold ascribed to weather, 1979–1997. Technology, 7S, 165–173.
Ching-Cheng Chang, Robert O. Mendelsohn, Daigee Shaw: 2003, Global warming and the Asian Pacific, Edward Elgar Publishing, ISBN 1843764199, 9781843764199, 307 pages (Chapter 11)
Hall, B. Hall of Records: 2009 Bruce Hall web site - supporting analysis here and here
Mendelsohn, R., Nuemann, J.E., 1994, Impact of Climate Change on United States Economy, Cambridge University Press, Cambridge
Trenberth, K. 2007: Predictions of climate. Posted on Climate Feedback, The Climate Change Blog, June 4, 2007.