September 25th, 2007 - REMEMBER SEPTEMBER 21

There are certain dates that we each remember. Christmas, Easter, Fourth of July, family members birthdays, anniversaries and a host of other dates. My wife is a list person and on her calendar she has all sorts of dates marked as special occasions. There are dinner dates, co-workers anniversaries and birthdays, what happened last year on a certain date, and the list goes on.

One date that I noticed that she had marked was September 21. It was marked “Today’s weather the same as November”. I asked her where she had heard this and the answer was that she did not remember. However every year she marks it on her calendar.

Being the curious person that I am, I started to look through my vast library of weather books and weather lore. Not one to brag, but being the weather –nut that I am, I have a rather good collection of books on the subject of weather and am constantly adding to it.

After considerable research, I could not come up with any reference as to the weather on September 21 being the same as November. However, from a book titled, “The Unique Bedside Book of Weather Lore”, published in Great Britain in 1950, I did find the following sayings:

“A quiet week before the autumn equinox and after, the temperature will continue higher than usual into the winter.”

“St. Matthew’s rain fattens pigs and goats.”

“St. Matthew brings on the cold dew.”

“Matthew’s Day bright and clear
Brings good wine in the next year.”

(It should be noted that St Matthew’s Day is on the 21st of September)

“South wind on 21st September indicates that the rest of the autumn will be warm.”
Finally, this is the one that comes the closest.

“These three days of September rule the weather for October, November, and December.”

The three days this refers to are the 20th, 21st, and 22nd, of September. In this case the 21st would indicate November.

Common sense should tell us that if it is 85 degrees on September 21st, the month of November is not going to be 85 degrees. November is going to be cooler than September. That is just the way it is and always will be. However, after more research, I compared November’s weather with the weather on September 21st and found some interesting facts. If the temperature on the 21st was above normal, the temperature tends to be above normal in November. If it is below normal on the 21st, November’s temperatures tend to be below normal. Not all the time but quite often. One thing I did not look at was the precipitation, nor did I figure the percentages, although they were above 50%. I will go back and look at the precipitation and figure the percentages and we will look at this again come November.

Quite often on these weather lore sayings, they refer to the weather for the next day or two. Most of the time they correctly forecast the coming weather. We now have a name for this and it is called “persistence forecasts”. What this means is that tomorrow’s weather will be similar to today’s weather. Using this principle, we are likely to be right more often than not, generally around sixty percent of the time.

I suppose you could also use this same theory predicting the weather for the next month or two. If the temperatures are above or below normal this month, they will be above or below normal next month or the month after.

All predictions are for a mild winter this year, but come the latter part of October, I will be putting away my shorts and tee-shirts and getting out my corduroy pants and flannel shirts.

Oh, by the way, don’t forget to write on your calendar for September 21st; today’s weather the same as November.

This entry was posted on Tuesday, September 25th, 2007 at 8:34 pm and is filed under Columns. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

Comments are closed.