October ranked as the 41st coolest on record in Fargo Moorhead. Although locally last month was not exceptionally cold for our climate, other parts of both North Dakota and Minnesota finished much colder. The National Climatic Data Center (NCDC) released their monthly statistics for last month earlier this week and found that taken as a whole, October ranked in the top 30 coldest on record in both North Dakota and Minnesota.
NCDC ranked October 2012 as the 23rd coldest on record in North Dakota and the 29th coldest on record for the state of Minnesota. The precipitation statistics also varied. Fargo Moorhead record 2.22 inches of rain and melted snow last month, right at the average of 2.15 inches, but taken as a whole, North Dakota recorded the 14th wettest October on record. There were several precipitation events in western and northern North Dakota last month that missed us locally or dropped lighter amounts of precipitation.
Minnesota on the other hand, like Fargo Moorhead finished right near the long term average for precipitation.
Last month finished with an average temperature of 44.0 degrees which is 1.5 degrees below the current 30 year average. If you thought the month felt cooler than that, you are likely not alone. Although the past two months finished near average, the past 18 months have been exceptional warm which has likely changed our perception of “normal” temperatures. Plus, last month’s high temperatures generally were much colder than the morning lows per the average and daytime temperatures tend to be more noticeable.
October recorded 2.22 inches of rain with is right at the current average of 2.15 inches. One element of the weather that was definitely not near the average last month was snowfall. There were two snow events in October, one on October 4 that dropped 1.4 inches and the other one on October 27 that brought another 2.2 inches.
That total of 3.6 inches may not sound like much, but it was the 11th highest October snow total on record.
The early October snowstorm prompted several inquiries as to the frequency of such events in the past. An October 7 snowstorm in 1985 brought a significant snow to areas just north of Fargo Moorhead with Grand Forks recording 6 inches, Roseau 8 inches, Langdon 10 inches and Velva, North Dakota recording 17 inches. October 1-2, 1950 brought 3-6 inches to areas near the Canadian border in both North Dakota and Minnesota.
From October 7-11, 1970, some parts of northern Minnesota had over a foot of snow that even produced some road closures. A severe blizzard struck northwestern Minnesota on October 18-20, 1916. Although, Fargo only recorded a trace and Grand Forks around 2 inches, other locations east of the Red River Valley were buried under 8-12 inches of snow from that event. Plus, most of us are familiar with the severe blizzard that hit to our south on October 16-18 in 1880 that was made famous by Laura Ingalls Wilder in her book “The Long Winter”.
Although the past two days were quite mild, as a whole, the first 15 days of October finished about 5 degrees below normal. That is an incredible 19 degrees colder than the first half of October last year. Although, it should be noted, that the first half of October 2011 was the warmest such period on record. The second half of 2011 and much of this year recorded above average temperatures.
Then the past two months, August and September, finished near normal and the current pattern, at least for now, has transitioned to a cold one. The last time with an extended period of below average temperatures was in May, 2011. Looking forward, it appears much of the rest of the month will record temperatures below normal, meaning that this month will likely be the coldest, based on the average, in 17 months.
This October has not only been cool, but also dry, with only 0.43 inches recorded through Monday which is 0.67 inches below average.
The average temperature in August is about 70 degrees, in September that fell to near 60 degrees and this month the average temperature plunges into the middle 40s. Although most years, like last month, September will bring the first frost of the season and a taste of the upcoming cold season, it is in October that it becomes obvious that winter is coming.
The average high this month will drop from 64 degrees on the October 1 to just 48 degrees on Halloween and the average low drops from 48 degrees to 29 degrees. October is also when we often record our first snow flakes of the year. Although the average first measurable snow does not occur until October 31, trace amounts are often observed earlier in the month.
The average snow fall in October is a mere 0.7 inches, with the average rainfall being 2.15 inches.
Since weather records have been kept in Fargo Moorhead, there have been occasional times when the observed weather was far more extreme than any other similar period. A couple of examples most readers will be familiar with was the exceptional heat wave during July 1936 or the severe cold snap in February 1936.
Another such period that few have heard about or remember was the warmth of October 1963. That month was by far the warmest October on record by 4 degrees. The other months in the top ten for that month all fall within two degrees of each other. The coldest high temperature that entire month was 52 degrees and on more than half the days the high was 70 degrees or higher.
There is the old saying that records are made to be broken, but like the other examples listed, that may be true, but another October like the one in1963 may not be experienced again for a long long time.
Although recent years have recorded some very mild autumns, the month of October has often been an exception. An example of this occurred just two years ago when the fall of 2009 ranked as the 9th warmest on record, yet, October 2009 finished as the 9th coldest since 1881.
That same autumn both September and November finished as the 2nd warmest such months on record. In fact, all of the Top 10 warmest Octobers occurred before 1964. The warmest October on record was in 1963 and following that year none of the next 47 Octobers finished anywhere near the Top 10. That has now changed. Last month finished with an average temperature of 52.7 degrees which ranked as the 6th warmest October.
Combined with September the last two months have ranked as the 9th warmest such period in the past 131 years and like October, the warmest such stretch since the fall of 1963.
Several years ago on this blog, I wrote about the connection between October snow cover in Siberia and winter temperatures in the United States. Of all the articles I have written, that one seems to be remembered the most as every autumn I tend to get numerous inquires as to what the snow pack in Siberia is this time of year. October is the month that records the greatest expansion of snow cover in interior Eurasia. The increase in snow cover in that region is often greater than the entire land area of the lower 48 states.
The theory goes that an early and expansive snow cover in Siberia will affect the pressure and wind flow around the Arctic that allows more frequent intrusions of cold air into the United States. Through the middle of this month, Siberian snow cover has been less than what was recorded last year, but according to the theory, it is total coverage at the end of the month that matters.
Preliminary numbers indicate that the average temperature in September was 59.9 degrees, which is 0.8 degrees above the current 30-year average. If you are thinking that last month felt warmer than just one degree above average you are not alone as I also thought the same thing.
Part of the illusion of last month being warmer than it really was can be attributed to the average high temperature being nearly 4 degree above average. Most individuals notice the high temperature more than the low temperature during the warm season, with the opposite being true during the winter. Those afternoon temperatures were likely enhanced by the dry soils and the overall low humidity levels that dominated much of the month.
Those same conditions that lead to warmer afternoon temperatures also are the same ingredients that make for cool morning lows. It was the low temperatures finishing nearly 3 degree below normal that kept the overall average temperature last month cooler than what many of us would have guessed.
October finished with an average temperature of 50.0 degrees which is 4.7 degrees above average. That was warm enough to rank last month as the 16th warmest October on record and the warmest October since 1994. Although we have recorded some very mild Septembers and Novembers in recent years, Octobers have generally been cold in recent decades. For example, October 2009 was the 9th coldest and 2002 was the 4th coldest and many Octobers in the past 40 years rank in the bottom 50% for average temperature.
In fact, all the Top 10 warmest Octobers occurred before 1964, with most of our mild Octobers recorded in the 1920s through 1940s. In other words, if you are less than 50 years old, the past 31 days was likely the 2nd warmest October you got to experience living in this area.
October finished slightly below average for rainfall with 1.91 inches officially measured in comparison to the average of 1.97 inches. But many locations picked up much more and with it coming all at once definitely made October much wetter than the official total would suggest.