Those dog days of August: 3 times the heat by 2050?

August 19, 2009
Scientists at Climate Central have analyzed climate change projections made with global climate models. Scientific literature based on these models anticipates much more frequent occurrences of hot days, “heat waves” and extremely warm summers. Credit: Climate Central / Remik Ziemlenski

If you are wilting under the summer heat, consider this: your child may one day think of summer 2009 as "back in the cool old days." To illustrate expected increases in extreme summer heat, scientists at Climate Central have analyzed climate change projections made with global climate models.

Scientific literature based on these models anticipates much more frequent occurrences of hot days, "heat waves" (very sustained over several days), and extremely warm summer seasons. Beyond being uncomfortable, these projected increases in extreme heat will have important societal impacts, including:

  • heat stress mortality in humans and livestock;
  • increases in peak energy demand;
  • crop damage; and
  • increased demand for water.
Climate Central's analysis of model projections suggests that across a large number of U.S. cities, the average number of days in August with temperatures over 95 degrees Fahrenheit could nearly triple by 2050, and the average number of days over 100 degrees could nearly double.

Climate Central's Associate Director for Strategic Initiatives, Dr. Ben Strauss, emphasizes that the numbers are not predictions. "We're talking about best estimates and averages," says Strauss. "No matter how close the projections turn out to be, some years will have more hot August days, and others will have fewer."

Climate Central is a nonprofit science and media organization created to provide clear and objective information about climate change and its potential solutions. Its work has appeared on PBS's The NewsHour with Jim Lehrer,,, Scientific American, and beyond. Staff scientists drew on regional scenarios from a dozen highly sophisticated computer climate models to compare 1980 and 1990 averages with 2050 projections in three categories:

  • Average number of days in August over 90.
  • Average number of days in August over 95.
  • Average number of days in August over 100.
All of these measures were projected to increase or stay level in every city analyzed. The bottom line is that locations across the nation are likely to experience significant jumps in the number of extreme hot days in August and other summer months, from New York to Los Angeles, and from Florida to the Midwest to Seattle, which just experienced an unusual heat wave earlier this summer. More information on the projections, the methods used and their limitations is available at

Worldwide, since 1995, tens of thousands of people have died in heat waves. Other important impacts include increases in demand for energy (particularly electricity for cooling), and increases in urban and agricultural water demand.

The severity of increases in extreme heat and their impacts will depend on the extent of future use of fossil fuels. "We do have some choice here," says Dr. Berrien Moore III, Climate Central's Executive Director. "How hot it will get will depend on the choices we make about energy and transportation in the years to come."

More information: "Weather and Climate Extremes in a Changing Climate. Regions of Focus: North America, Hawaii, Caribbean, and U.S. Pacific Islands." U.S. Science Program Synthesis and Assessment Product 3.3 (June 2008). Available at

Source: Climate Central

Explore further: European heat waves double in length since 1880

Related Stories

European heat waves double in length since 1880

August 3, 2007

The most accurate measures of European daily temperatures ever indicate that the length of heat waves on the continent has doubled and the frequency of extremely hot days has nearly tripled in the past century. The new data ...

Climate may increase heat-related deaths by 2050s

September 27, 2007

While some uncertainty does exist in climate projections and future health vulnerability, overall increases in heat-related premature mortality are likely by the 2050s, according to a recent study by Columbia University’s ...

More Intense Heat Waves Could Slam California's Energy Grid

September 19, 2005

Climate change and rolling blackouts may be a package deal. More frequent and intense heat waves expected in California over the next 100 years could overburden the state’s electric utility grid, according to a study led ...

Recommended for you

Scientists dispute missing dryland forests

November 21, 2017

Scientists are disputing the possibility that a significant portion of the world's forests have been missed in an earlier accounting of ecological diversity.


Adjust slider to filter visible comments by rank

Display comments: newest first

3.4 / 5 (5) Aug 19, 2009
What is with the old data? Could they not have used something newer than the period they used? I mean, people in my area are talking early Fall this year because the overall temps have been lower than normal.

Over the last few years there has been an overall cooling trend. Just this week we used no cooling whatsoever and the indoor temps never rose to higher than 78°F (25.55555555555556°C).

This lasted for at least three days. Today, the high was 88.6°F (31.44444444444444°C).

I have never experienced an August Summer like that in all the decades I have lived.
3.4 / 5 (5) Aug 20, 2009
Why don't they project how many people die from colder winters. If your going to stop the alleged warming you might end up reversing it and bring about far more deaths from cooling. Not that I think we can do either warming or cooling...
2.3 / 5 (6) Aug 20, 2009
hey there dachpukeville.. you might want to take a chill pill and wait for next summer. This year`s summertime low temps are a freak incident. This will happen only very rarely....
2.1 / 5 (7) Aug 20, 2009
so says the great guru zbarlici, the all knowing understudy to Al Gore and the rest of the meatheads !
3 / 5 (4) Aug 20, 2009
hey there dachpukeville.. you might want to take a chill pill and wait for next summer. This year`s summertime low temps are a freak incident. This will happen only very rarely....

Oh, you mean like last year's "freak incident" that was not supposed to be duplicated and the year overall warmer than 2008 predicted by the computer models?

You mean, like the NSIDC predicted ice-free Arctic of 2008 that never happened?

Ummmkaaay... Uhuh....
1 / 5 (3) Aug 21, 2009
Yeah.. people have had a gut full of this global warming crap.

Solar activity on the Sun has died down and will remain subdued until at least mid 2030's. This means that we will have a 30 year cooling period comparable to the Dalton Minimum from 1790 - 1820.

But don't expect the pseudo-scientists who run this web site to recognise this. They will still be predicting warming when world temperatures reach a minimum in 2030.
1 / 5 (1) Aug 21, 2009
Yes it has slowed down--again. Just checked SOHO data over the last few weeks. There were spots during a couple days in mid-July but these are now gone. As of yesterday evening I have seen not a single visible dark spot clouding the MDI Continuum data of the Sun.

Yet another prediction bites the dust! The Sun was supposed to have returned to activity months ago. :)
1 / 5 (2) Aug 22, 2009

See: "EARTH'S HEAT SOURCE - THE SUN", in Energy and Environment (SPECIAL ISSUE: Natural drivers of weather and climate) volume 20, numbers 1 & 2, pp. 131-144 (2009)

With kind regards,
Oliver K. Manuel
1 / 5 (1) Aug 22, 2009
Could we not experiment with terraforming in the lab ? I feel a little uncomfortable being a little white mouse ...
not rated yet Aug 29, 2009
Scientists tried that--and failed. Remember Biosphere 2? Their equipment was insufficient to remove CO2 in sufficient quantities to keep the experiment habitable to the scientists living in the sealed structure.

They have since upgraded the equipment and vent CO2 to the outside but it only functions as a laboratory now rather than a "terraformed" type experiment.

CO2 in the real world, even at the rate in which it is going into the atmosphere, is not going to kill you and it certainly will not turn the earth into another Venus.

Earth does not have enough CO2 in the atmosphere to do that. Even if we burned everything organic on the planet we would not have enough.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.