I really like to sift through past weather data, looking for patterns and trends. One that came to mind recently was: does an early heat spell, like the one we had at the start of May, give any clues about the upcoming summer?

So I looked back at all the years when we had a period of early heat - say, at least two 90^oF days before May 15th. That's happened 12 times in the last 100 years. And I asked - is there any pattern in the summers that followed?

The answer is "not really". While some of the summers that had early May heat spells turned out hot...some didn't - on average, they were nothing special temperature-wise.

Now, this simple analysis doesn't prove or disprove anything about temperatures this coming summer. It just illustrates that our weather is changeable from month to month ... so simple correlations usually don't work.