Early Michigan weather stats

 

When I mention weather records I like to use the term “recorded history” and the reason for that is most weather records in Michigan (and most of the rest of the United States) only go back to the later 1880’s. Here in Michigan we have one location (Lansing) that goes back to 1863 while Detroit goes back to 1874 and Sault Ste Marie officially goes back to 1889. Here at Grand Rapids it record only goes back to 1894. So we do not have a good record of what the weather was like before the late 1880. In Michigan the British took temperature readings at Fort Detroit from 1781 to 1786 but the Americans did not keep records there until 1874. The longest official records here in Michigan are from Lansing where they started in 1863. However, at Sault Ste Marie there are some good records from 1823 until 1857. There is a long gap from 1858 until 1889 however. Back in the 1823 to 1957 period at the Sault the temperature was taken and recorded 3 times a day at 7 AM 2 PM and 9 PM. One item I would now like to cover is how we determined what is the “average” as in average high or low temperature or average snow fall etc. The United States uses a floating 30 period for a average. So that at this time the “average” is based on the weather records from 1981 to 2010. And will be updated after 2020. For Michigan as a whole the warmest years are scattered over the states recorded history with 2012, 1846, 1921, 1987 and 1878 being the warmest and 1875, 1917, 1885, 1888 and 1883 being the coldest point to a possible very cold period in the l875 to 1890 time. As for precipitation there is more year to year variability but more stable of the long term. The wettest year 1985 is almost twice as wet as the driest year 1930. And there have been wet years after dry years. While there have been multi dry years leading to droughts 1934-1936, 1962-65, 1987-1990 long term droughts in Michigan are rare.

OK here is some climate/weather information from some very early Michigan climate and weather observations. Note many of the observations are not official and most were at a time when the reading were taken 3 times a day. Also no one knows just how accurate the instruments were and just how honest the people taking the readings were.

First installment 9000 BC to 1821

 

9000 BC the ice sheets retreats to the north and leaves what is now Michigan and the Great Lakes in its place (note it take almost a 1000 years for the ice to melt from south to north over Michigan.

3000 BC What are now Lakes Michigan and Huron reach their highest levels at about 20 feet above current levels  This is deduced by elevations of ancient beaches. The high water level very well may have been due to a different drainage set up as the levels dropped once the channel that is now the St Clair river opened up.

700 to 1000 AD Lakes Michigan and Huron levels fall to about 5 feet below the current levels so there may have been a 300 year period of dryer weather over the Great Lakes. It could even have been warmer.

1000 to about 1800 the lakes run 5 to at times 10 feet higher than present levels there was however a time between about 1250 to 1500 when the lakes were near their current levels and the lakes at that time there is a chance the climate was near what we have now.

1781 Dr George C. Anthon a British Army Post Doctor at Fort Detroit started his “Meteorological Journal” he kept the journal for 5 years.

1784 Dr Anthon journal states that the temperature falls to -7 on January 7^th and the Detroit river freezes over. He reports the temperature falls to -15° on January 9^th and 16^th down to -22 on January 25^th and reports readings of – 20 January 27^th to the 30^th He reported a “thaw” at the start of February but back down to -12 on the 8^th and -18 on the 9^th February ends with a -10 on the 29^th Readings of -6 on March 4^th and a -4 on the 5^th were reported. He reported 23 sub zero readings for the winter.

1821 The Detroit Gazette reported a reading of -27° on March 8^th and 8” of snow on April 18^th in Detroit.

Here is some information of Fort Detroit

https://en.wikipedia.org/wiki/Fort_Detroit

 

To be continued next week

Slim