BJ Price
I am not a meteorologist by trade, nor have I ever played one on TV. As the weather outside trends cooler and the leaves turn colors and drop, I hear folks talk about Indian summer. Some refer to it as ‘second summer’ or ‘poor man’s summer.’ While the word ‘Indian’ is not used in as many places as it used to be, I don’t seem to come across any pushback with Indian summer. We associate it with a spell of nice weather in the fall, but can there be a better working definition?
Going to my trusty red-backed Webster’s Dictionary, Indian summer is defined as ‘a period of mild weather in late autumn or early winter.’ While that is certainly a definition, I’m just not sure that captures the essence of it. What if the weather stays mild for a long period of time spanning from late summer leading into winter? That would fit within the confines of Webster’s definition but it doesn’t feel like an Indian summer.
William Deedler, a Weather Historian who was employed by the National Weather Service, defined Indian summer as ‘any spell of warm, quiet, hazy weather that may occur in October or even early November.’ This matches up with the Webster’s Dictionary definition, but I’m still a little hazy myself on the true meaning.
The Farmers’ Almanac (around since 1818) defines Indian summer with more exact terms. They have a two-fold definition. First, ‘temperatures must be above 70 degrees Fahrenheit for a period of … seven days or more after the fall equinox.’ Second, ‘the heatwave must occur after the first frost.’ To summarize, it needs to be a week in the 70’s after the season changes from summer to fall and after the first frost. I think this is the definition I’ll go with. If it gets cold enough to frost, that means we’ve had some chilly overnight lows. To go from having nighttime lows in the 30’s to a stretch of daytime temperatures above 70 degrees would feel like summer to me.
The weatherman tells us that Indian summer is typically caused by a sharp shift in the jet stream from the south to the north. The warm weather may last anywhere from a few days to over a week and may happen multiple times before winter arrives for good.
The forecast calls for patchy frost the middle of this week. If it does indeed frost, watch out for a week with temperatures in the 70’s, then we’ll know we’ve had an Indian summer. Looking ahead several months, is anyone wondering what an old-fashioned winter looks like?
Reach BJ Price at 937-456-5159 for more information.
