Heat wave in perspective

As mentioned in our story (and, no, we do not write the headlines) in today's Inquirer, this heat wave is entering the rarefied atmosphere in local weather lore.

We also noted that we have had longer heat waves, and we have had more-intense hot spells.

By day's end Saturday, the average temperature for the 10-day period will come in right around 84.8.

We found hotter 10-day stretches in 10 other summers. The king would be the one that ended July 13, 1993, 87.2 degrees.

We remember that one particularly well since our son was born on July 12 that year. (Actually, one of us remembers it even more well.)

The other hotter 10-day periods occurred in 1896, 1901, 1953, 1973, 1995, 1999, 2002, 2006, and 2011.

Two things jump out at one about that sequence. Hot spells aren't a modern invention, but the modern era dominates the top 10.

At the request of forever-youthful friend Signe Wilkinson, cartoonist and crypto-climatologist, we reiterate that all rhetoric aside, the world has grown warmer over the last 30 years.

But the month-to-month variability typically is on the order of tenths of degrees. So if a month is 5 degrees above normal in one part of the planet, it would have to be quite cool someplace else.

The warming effects would not be uniform, any more than the cooling effects of the aftermath of the Mount Tambora eruption in 1815, or Pinatubo, in 1991, or the Little Ice Age, from the Renaissance to the Industrial Revolution.

Stay cool, even if you get into a discussion about global warming.