The ancient Romans considered the hottest days of summer to be when the dog star Sirius appeared in the sky. Today, that would be primarily in August. This strikes us in the Western Hemisphere as very odd, since August is the month that our summer starts waning.

For the ancient Romans, the dog days of summer occurred from about July 24 to around August 24. -- Wonderopolis

To us in the United States, the hottest days of summer would usually be July.

The Old Farmer's Almanac lists the traditional timing of the dog days of summer as being July 3 until August 11. -- Wonderopolis

The explanation for this difference in ancient and modern timing is that the dog star Sirius has drifted in the night sky over the millennia; but there is more this than meets the eye to this -- and it involves more than constellational drift.

Here, in the Western Hemisphere, July is the scorcher in our calendar year; and that is what we would expect. July is the height of summer with longer days than August.

However, in the Mediterranean basis, a curious meteorological phenomenon occurs. Nice, France is hottest in August. The same is true for Barcelona, as well as Messina, Italy, Malta, Genoa, Italy, and Athens, Greece. It would seem that, independent of constellational drift, August really was the hottest month to the Romans.

The explanation for this unexpected -- at least to us Americans -- climate is the Mediterranean basin. The Mediterranean heats up slower than the landmass, and thereby holds heat longer. As the sun wanes in August, the Mediterranean starts to slowly shed the heat that it had stored up during June and July. Added to that are the Sirocco winds from North Africa. Likewise, during the winter, the Mediterranean sheds what remains of its stored heat to keep the coasts from going into a hard freeze. As the landmass heats up in spring and early summer, the Mediterranean is still cool enough to moderate the rise in temperature… until August, when the process reverses again.

Though Nice and Barcelona are at latitudes roughly equivalent to Toronto and Chicago respectively, they can support coastal palm trees. The massive heat sink of the Mediterranean seems perfectly designed to moderate the climate that it would enable European civilization to flourish. The Mediterranean has long, dry summers, and mild rainy winters, with almost no snow along the coastal areas. This is where Greek civilization arose. This is where Rome (which by the way has the occasional palm tree) arose, even though it is at the latitude of Stamford, Connecticut.

This is why the French all seem to prefer taking their summer vacation in August.

If you walk around Paris these days, you'll see tourists, but not many Parisians. French people are on vacation, and the streets are deserted. But the emptying of the capital is not entirely voluntary. Many French people are obliged to take the bulk of their holidays in August, because their workplaces are closed. -- Network Europe Radio

It seems so crazy. July has longer evenings, later sunsets. It makes no sense to take a summer vacation in August until one understands that the Mediterranean makes August the warmest month in Southern Europe, and the ancient Mediterranean set the clock and practices for much of the rest of Western Europe.

And not just Europe. Beirut's hottest month is also August, and the same for Tel Aviv.

Here in the United States, the region of approximate Mediterranean climate in the California coast from San Francisco to Los Angeles, though the exact mechanism is different.

What is interesting is that across the globe, wherever Mediterranean climates abound, civilization abounds as well as prosperity. How could it be otherwise. Such a pleasant climate makes life easier. This is true for California, Central Chile, Western Australia, except …

Except when it comes to Islamic areas. Northern Africa is blessed with what arguably is the best climate on the planet. Were North Africa the possession of Germans or Japanese, one could only imagine that it would be fully developed and the most pleasant spot on the globe to live.

The ancient Romans were eager to conquer North Africa, and the whole region is today littered with the ruins of Roman metropoli.  Roman planted colonies of veterans in the area. North Africa became the granary of the empire. Romans would retire to North Africa, the way our elders retire to Arizona or Florida.

Yet, when Islam took over, all of this stopped. The chief condemnation of Islam is that it kept the South Mediterranean basin from developing. This is what the dog days of summer have to tell us. For those of you yet to vacation, reflect on that as you sunbathe.

Mike Konrad is the pen name of an American who wishes he had availed himself more fully of the opportunity to learn Spanish in high school, lo those many decades ago. He writes on the Arabs of South America at http://latinarabia.com. He also just started a website about small computers at http://minireplacement.com.