Space Weather

Saturday, October 9, 2010

What is Indian Summer?

Indian summer is a weather phenomena that occurs during the autumn months across the  United States. It is often a period of weather marked by sunny or hazy sunshine during the afternoon and accompanied by mild temperatures.


Unlike a heat wave (as defined for the Northern U.S. which is a period of 3 or more consecutive days that have a maximum temperature of 90 degrees Fahrenheit or higher), Indian Summer has no true definition as to what defines it.


Some meteorologists say the daytime temperature must be at or above 70 degrees. The only problem with this "condition" is that e.g. for Albany, NY in November the average maximum temperature for  November 1st is 53 degrees, by mid-month its in the mid 40s and by the last day its 41 degrees. My personal preference and again this is my preference is that if the daily high temperature is 10 degrees or more above normal, I consider it to be Indian Summer.

Perhaps the only truism regarding Indian Summer is that it is the first "spell" of mild weather that follows the first widespread hard frost or freeze (some also say the leaves must also have turned color, too) and it occurs before the first snowfall. Thus usually the period from around mid-October through November can see Indian Summer or Indian Summers (more than one such period of balmy weather). Some years can also have no Indian Summer either.

Why am I writing about Indian Summer?

Well, tonight appears as if we will experience our first widespread frost across interior sections o eastern NY State and in some of the lower elevations (of the Upper Hudson and Northern Mohawk Valley) a hard frost or freeze might occur. 

If this frost and freeze does materialize then the next spell of warmer than normal temperature(s) could be Indian Summer.

But wait!

The leaves have yet to completely turn!

3 comments:

  1. We're due for some 60+ temps this next 4 days, but does that qualify as "Indian Summer"? Since the average for October is in the 60's? Not going to be 10 degrees warmer?

    ReplyDelete
  2. Anonymous - Technically not Indian Summer; at least not in either my opinion or the loose definitions as I posted above. A nice stretch of weather for sure but not quite Indian Summer

    ReplyDelete

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