No matter what you call it, the weather this week has been fantastic. Anytime the high temperature approaches 80 degrees in early October with blue sky and a ton of sunshine, it’s a bargain. The common question with this weather: is this Indian Summer? And if it is, is this the last hurrah for warm weather this autumn?
Technically speaking, Indian Summer is considered to be a period of above-average temperatures following a strong frost. Defining a strong frost is a bit sketchy, although there is no denying that this is a period of above-average temperatures. Our average high for this week is 63 or 64 degrees. Mid to upper 70s is well above average.
Also, there is no law of nature that claims we can only have one Indian Summer. Warm stretches of weather in October or November are not uncommon, and they can come in multiple numbers. We can have a similar warm-up a month from now. And there can be some autumn seasons when we have no Indian Summer.
Officially in Milwaukee, at Mitchell International Airport, the coldest morning low this season has been 39 degrees on October 2. There was some patchy frost in some urban locations, but remember that Mitchell Int’l. is in more of a city environment where it tends to remain warmer overnight. Inland locations have experienced several frosty mornings this autumn, seeing morning lows drop into the low to mid 30s.
Based on inland frost, this week’s weather is Indian Summer. Based on the official temperature at MKE, not so much. But who cares? Whatever we call it, let’s enjoy it.
The origin of the term can be traced back over 300 years. Indian Summer was probably reserved for the time of year after the first snowfall of late autumn melted and Native American tribes would raid settlements of the European colonists. The melted snow meant it was more difficult to track the Indians back to their camp.
Or Indian Summer referred to a time when the Native Americans would use the brief warm spell to harvest their crops before the snowfall of winter arrived. In Europe, especially France, this time period was also known as Saint Martin’s Summer based on the feast day of St. Martin, November 11. Once this date was past, the snowfall was expected to stick around all winter.