The first half of autumn is nearly complete and the past 6 weeks have been one of the warmest starts of fall since 1881. This year continues the trend of milder autumns that this area has recorded in recent years. This trend of warmer temperatures this time of year has increased the average temperature for September, October and November by 1 degree. The average autumn temperature from 1971-2000 was 43.5 degrees and our current 30-year average from 1981-2010 is 44.5 degrees.
Some of you may take this as a sure sign of global warming, except, the average fall temperatures from 1931 through 1970 was also 44.5 degrees. You see, a series of cool falls in the 1970s and 1980s caused an over decrease in the average and our recent stretch of mild autumns has help increase our autumn temperatures closer to the long-term average after a brief period of cooler conditions.
This is yet another example of how climatic conditions subtly change over time.
At the end of each decade, a new set of averages is computed based on the last full three decades of data. Since 2001 our averages have been based on the years 1971 through 2000. Beginning this year the new averages are based on the years 1981 through 2010. As of July 1, these new normals have become official.
For anyone living through the 1970s, you likely remember how cold most of those years were. It was a very cold decade not only locally but throughout the United States. It was the era when many thought a new ice age was coming. Now that the 2000 decade that finished with average temperatures has replaced the cold 1970s in the computation of the new climatic stats, almost all locations have a higher overall average temperature, including here in Fargo Moorhead. This increase has been approximately 0.5 degrees over the country including here in Fargo Moorhead.
Our currently yearly average temperature is now 42.2 degrees up from the previous average of 41.6 degrees.
Every January I get inquires asking two specific questions. The first deals with when the average high and low temperatures start to increase. The average high temperature in Fargo Moorhead started to increase on January 19, when the average high went from 15 to 16 degrees. The average low temperature did not start to increase until January 22 when the average low increased from -3 to -2 degrees. Our average temperatures, be it slowly, will now increase until the middle of July.
The second question asked this time of year deals with the sunset occurring after 5:00 PM. If you work the traditional 8 to 5 shift each day, for several weeks you go to work in the dark and then drive home in the dark. If you are one of those drivers, you have certainly noticed the later sunsets. A few days before the winter solstice, the sunset at 4:38 PM in Fargo Moorhead and approximately one month later the sun is setting around 5:20 PM, finally giving many of you a glimpse of the sun as you are heading home.
One of the most common questions asked this time of year deals with when the average high and low temperatures start to increase. There is something about the averages starting to rise that brings a sense of relief to many individuals. Starting today, the average high has started the slow climb upwards.
Yesterday the average high was 15° and today it is 16°. Our average low on the other hand will wait until tomorrow for the increase to begin. The average low today is -3° and tomorrow it will increase to -2°. The averages will increase very slowly the next couple of weeks. By the end of the month the averages will be 18° and 0°. In February we will gain a degree about every four days and on February 28 the averages will be 27° and 11°.
The milestone I look forward to is the day our average high finally reaches 32° and that will not occur until March 10.
The average low temperature in Fargo Moorhead dropped to -1° on December 28 and it will remain below zero until January 30 when the average low climbs to 0°. The average low will drop two more degrees to -3° on January 6 and remain there until January 22. Thereafter, the average low will begin its slow raise that will peak at 60° on July 15.
Our average high bottoms out at 15° on January 11 and stays there until January 21 then begins a climb that will end on July 17 when our average high will peak at 83°. Although the average low temperature is below zero on 34 days during our cold season, Fargo Moorhead averages 48 negative days per winter.
So far we have recorded 12 below zero days, which happens to be right on the average for this point in the winter season.