TheClimateChanger

Some more October monthly records set or tied today, including 87F at Marquette, Michigan, and 83F at Sault Ste. Marie, Michigan. Traverse City reached 88F, falling 1F short of the monthly record set on October 2, 1922. International Falls, Minnesota reached 87F, falling 1F short of the monthly record set on October 5, 1963, and October 11, 2015. Brainerd, Minnesota reached 88F, falling 1F short of the monthly record set yesterday. Green Bay reached 87F, falling 1F short of the monthly record set yesterday and on October 6, 1963. St. Cloud, Minnesota reached 90F, falling 1F short of the monthly record set yesterday. Fun fact for Brainerd: they had the 2nd and 3rd highest temperatures ever recorded in the month of September last month (102, on the 3rd; and 97, on the 4th), and now have the first and second (tied) highest temperatures ever recorded in the month of October (89 yesterday, and 88 today). It also reached 88 on October 2, 1992, and October 2, 1953. Not bad for a POR dating to 1898.

Determining specific temperature records for southeast Pennsylvania from 1000 years ago (around the year 1023) is extremely challenging because there were no direct temperature measurements or climate records during that time. To estimate past climate conditions, scientists rely on various proxies and historical data sources, such as tree rings, ice cores, sediment layers, and historical documents. Based on these sources and general climate knowledge, we can make some broad inferences about what temperatures might have been like in southeast Pennsylvania around 1000 years ago: Medieval Warm Period: Around 1000 years ago, the Earth experienced a period known as the Medieval Warm Period, which lasted from approximately the 9th to the 13th century. During this period, temperatures in various parts of the world, including Europe and North America, are believed to have been warmer than during the subsequent Little Ice Age (which occurred roughly from the 14th to the mid-19th century). Regional Variability: Climate conditions during the Medieval Warm Period were not uniform across the globe or even within regions. Some areas may have experienced more significant warming than others, and regional variations in temperature and climate patterns were common. Warmer Winters and Milder Conditions: Generally, the Medieval Warm Period was characterized by milder winters and longer growing seasons compared to the subsequent Little Ice Age. This could have had implications for agriculture and settlement patterns in southeast Pennsylvania. It's important to emphasize that our understanding of past climate conditions is based on various indirect sources and reconstructions. Specific temperature data for southeast Pennsylvania during that period would require more detailed research and analysis by climate scientists, using localized proxies and historical records. These studies can provide a better understanding of regional climate variations during the Medieval Warm Period and other historical periods.

Determining the exact temperatures in a specific region like southeast Pennsylvania 500 years ago is challenging because we don't have direct temperature records dating back that far. To estimate past climate conditions, scientists rely on a variety of proxies and historical data sources, such as tree rings, ice cores, sediment layers, and historical documents. Based on these sources, we can make some general inferences about the climate in southeast Pennsylvania around 500 years ago, which would be approximately in the early 16th century (around 1523-1524). During this time period, the Earth was in a period known as the Little Ice Age, which lasted roughly from the 14th to the mid-19th century. This period was characterized by cooler temperatures compared to the present day. In southeast Pennsylvania during the Little Ice Age, you might expect: Colder Winters: Winters were generally colder and more severe, with more frequent snowfall and ice. Shorter Growing Seasons: The growing seasons for crops would have been shorter due to cooler temperatures, potentially impacting agriculture. Glacial Activity: Some evidence suggests that glaciers in North America, including the nearby Appalachian Mountains, may have advanced during this time. Climate Variability: The Little Ice Age was not a consistent period of unchanging cold; it had periods of colder and milder temperatures, with regional variations. It's important to note that the climate during this time was not uniform across the entire 500-year span, and there would have been natural variability from year to year. To get more precise temperature data or climate reconstructions for southeast Pennsylvania during that period, you would need to consult specific research studies and climate reconstructions that focus on the region. Climate scientists use various methods and proxies to estimate past temperatures, and these studies can provide more detailed insights into historical climate conditions.

I didn't claim it was "way above normal." I said it was well above the median of all years, which it was. Here is ABE: 37th warmest, of 101 years. So a bit of a cool outlier, but, indeed, still above the median, which would be 50th/51st place. Sorry, if the "community notes" aren't appreciated, but I'm a big fan of that feature on X. I think providing useful context to any post that might be misleading is a good thing. Better than simply saying "lol", no?

Community Notes: The official, first-order NWS sites nearest western Chester County all show September 2023 as well above the long-term median. Hagerstown, MD (27th warmest out of 125 years) Harrisburg, PA (24th warmest out of 136 years) Reading, PA (27th warmest out of 128 years) Baltimore, MD (21st warmest out of 152 years) Philadelphia, PA (23rd warmest out of 150 years) Wilmington, DE (31st warmest out of 110 years)

Community Notes: To date, it has been the 11th warmest year on record at DTW (out of 150 years). Prior to 2006, only 4 warmer starts to a year were observed (1921, 1998, 1991, and 1955). In the 117 years from 1874 to 1990, only 2 years were warmer (1921 & 1955).

I mean it hasn't exactly been record-breaking like at MSP, but the period from August 1 to the present is 13th warmest (of 155 years) in the Madison Area threaded record. Only 5 years were warmer since records moved to MSN Airport - 1947, 1948, 1955, 1959 & 2016. Since 1959, only 2016 was warmer than this year has been since August 1. And there has been some bouts of significant heat. Again, while not as impressive as the heat in Minneapolis, some of these monthly values have not been exceeded in decades. In August, MSN reached as high as 96. Only 11 out of 155 years exceeded that value, and none since 1995. Prior to this year, it had not even reached 95F in August since 1995. In September, MSN reached as high as 94F. Only 7 out of 155 years exceeded that value in the month of September. The last time it was warmer in 1978, when it reached 97F. It did also reach 94F in September 2013. And although October is only one day old, yesterday's high of 85F has been exceeded in only 9 years (out of 155 years of record) in the month of October. Point-click is forecasting 86F for MSN today.

Thank you. Also, mean maximum temperature since August 1 is 2nd warmest on record, mean average and mean low temperature are both records for that period - the mean average temperature by a whopping 1.2F, and mean low temperature by 1.5F. Those are massive jumps for a 62-day period! Mean maximum Mean Average Mean Low Interestingly, 17 years had mean average temperatures at or below the mean mimimum temperature from 2023 for this period: And 14 years had mean maximum temperatures less than or equal to the mean average temperature of 2023:

Minneapolis has done quite well in the heat department for the end of summer and early autumn. August A significant heat wave in late August brought numerous hourly monthly heat index records. Hourly data only going back to 1945 - all from MSP. It was only the 4th year to have multiple days at or above 98F in the month of August: The low of 79F on August 23rd was the 6th highest on record, missing the monthly record of 80F (which has been set 5 times) by 1F. The mean temperature of 88.5F on the 23rd was the 4th highest ever observed on any day in the month of August (chart below lists third, but there were two instances of 89.0F in 1947). The only higher are 89.5F, on 8/6/2001, and 89.0F, on August 4, 1947 & August 5, 1947. September September 2023 was one of only 6 years to have 2 days at or above 97F, in the threaded record. It was the first time that has occurred since 1939. It was also one of only 6 years to reach or exceed 98F in the month of September, and the first time that value has been reached since 1976. The daily mean of 86.0F on the 3rd and the 4th tied for 3rd highest daily mean ever observed in the month of September in the threaded record (chart below lists third, but there were two instances with a warmer daily mean in 1931). The low of 75F on September 3rd tied for 4th highest observed, and tied 2002 & 2015 as the highest since 1953. The only higher minima were 77F on September 5, 1912 & 76F on September 2, 1953 & September 9, 1931. Looking at hourly temperature readings at MSP back to 1945, 16 hours set or tied the highest observed in the month of September. October The high of 92F on the 1st is the highest maximum temperature ever observed in the month of October. It was also only the third occasion where the temperature has reached 90F in the month of October. The low of 69F on the 1st tied for 4th highest ever observed in the month of October, behind October 8, 2011 (71F), October 6, 2007 (70F), and October 3, 2005 (72F). The mean temperature of 80.5F on the 1st broke the monthly record by 2F: 9 of 24 hourly temperature records for the month of October (since 1945) were set yesterday:

Incredible. Closer to home, there were quite a few October monthly records - highest recorded maximum and/or minimum temperatures for the month - over the Midwestern U.S. yesterday. They've had some pretty impressive late season heat this year - with record-breaking heat indices for the month of August, and in some cases, all-time, in late August; a major heat wave in early September, which broken many daily records and approached/exceeded monthly records in some spots, and now an impressive heat spell here to begin October. It hasn't translated east much, however.

Some other notable records from Minnesota. 91F, at St. Cloud, is a new daily and monthly record. The prior monthly record was 90F, set on October 2, in 1992 & 1953. Prior to today, the latest day to exceed (not just reach) 90F was September 22, 1936, when it reached 92F. 89F, at Brainerd, is a new daily and monthly record. The prior monthly record was 88F, set on October 2, 1992. Brainerd has been no stranger to anomalous, out-of-season heat in recent times. Just last month, it reached 102F on September 3rd, which was only the 2nd time it has reached into the triple digits in the month of September, and was just 1F shy of the September monthly record of 103F, set on September 10, 1931. Brainerd hit 100F on June 4, 2021, and on June 20, 2022, which are two of only three 100+ days in the month of June (the other being the 100F reading on June 19, 1988). The only earlier 100F+ was May 31, 1934. 83F, at International Falls, tied the daily record but was well shy of the monthly mark. Still only 5 days in the month of October have eclipsed that reading - 87F, on October 2, 1912; 86F on October 2, 1953; 88 on October 5, 1963; 84F on October 5, 1970; and 88F on October 11, 2015. 90F, at Rochester, set a new daily record but was a few degrees shy of the monthly record. Still it was one of only four 90F+ days ever observed in the month of October - the others being 93F on October 3, 1997, and 90F on October 2, 1953, and October 9, 2010. It is the latest in the year for two consecutive 90F or better readings, however. Wisconsin also had some notable readings. The 88F reading at Green Bay tied the monthly record set on October 6, 1963. LaCrosse reached 91F, which while 1F below the daily record, is notable as only the 4th 90F+ reading on record there.

Minneapolis actually reached 92F today, which as noted is the new monthly record, and only the third reading at or above 90F in the month of October. Prior to today, the latest date in the calendar year on which it reached or exceed 92F was September 22nd, when it reached 95F in 1936 & 94F in 2017.

Some other noteworthy readings from Iowa, from sites with threaded records dating back to the 19th century. It reached 91F at Cedar Rapids, setting a daily record. This is only the 11th day on record in the month of October to reach or exceed 90F, and the first since October 3, 2006. Only three days were hotter - 94F on October 3, 1997; and 92F on October 2, 1953, and on October 6, 1963. Waterloo, Iowa reached 93F, setting a daily record. Only three days in the month of October have been hotter - 95F on October 3, 1997; October 6, 1963; and October 12, 1930. It was also the first time it has reached or exceeded 90F in the month of October since the 95F reading on October 3, 1997. Des Moines reached 91F, one shy of the daily record. However, it was only the 13th day in the month of October to reach or exceed 90F, and the first since it reached 92F on October 3, 1997.

Reached 95F at Spencer and Oskaloosa, Iowa, just a couple degrees below the statewide record high of 97F for the month of October, set on October 3, 1938, at Onawa; October 4, 1938, at Knoxville; and October 5, 1963, at Forest City and Shenandoah. The high of 95F at Spencer, broke the daily record by 4F, and also eclipsed the prior monthly record of 93F, set on October 2, 1997 and October 5, 1963. Spencer has now reached 95F or better on three consecutive days. Looking through the records, the latest stretch of 3 consecutive days at or above 95F, was September 12-15, 1939, when it exceeded that mark on 4 consecutive days. It also looks like last year had some notable late season heat at Spencer, Iowa. It reached 101F on September 20, 2022, which was the latest 100F reading on record by a week. The prior record was 100F on September 13, 1939, during the aforementioned 4-day stretch of extreme heat. That reading is the only other reading of 100F or better after September 4th. Records at Spencer date to 1895.

Per Maximiliano Herrara on X, the Iowa state record high for October is 97F. I saw a couple sites reached that today on the state roundup and he indicated temperatures as high as 99F may have occurred near the Nebraska border.

Also, looking at the table, only 10 days have ever reached or exceeded 90F at Cedar Rapids in the month of October: October 1, 1976 (90F); October 1, 1897 (90F); October 2, 1953 (92F); October 3, 1997 (94F); October 3, 2006 (90F); October 3, 1897 (90F); October 4, 1938 (91F); October 4, 1897 (90F); October 6, 1963 (92F); and October 10, 1962 (90F). Three of those dates were in 1897, so only 8 unique years since 1893. While 94F seems unlikely at KCID tomorrow, 90F is certainly possible. Fairly rarified air for October, should it reach that temperature. Would be only the 11th 90+ day on record in October, and 9th year to reach 90F or better in the month of October (and first since 2006).

Wow! Very impressive reading. Breaks the daily record by 3F. Dating to 1893, only one year had a later reading of 94F or better - 1997, when it reached 94F on October 3. Obviously, that means had it reached that temperature on tomorrow's date, it would have tied a monthly record for October.

Well, maybe sobering was too dramatic of a word. Certainly, the warmer minima are a blessing for farmers completing their fall harvests. With that said, it does raise important questions about the speed and extent of the environmental changes occurring since the plant and animal life in a region may have evolved in a manner that depends on frosts or freezes occurring by a certain date, or temperatures reaching a certain level of coldness over the winter [i.e., potentially to kill off parasites, which may harbor disease]. Although just outside this subforum, if we look at Hagerstown, Maryland, we see sub-40F lows in the month of September are now rarer than subfreezing lows were historically. That's a significant change. Since 2000, only year has had a low temperature less than 40F (2020, when it dropped to 38F). Conversely, 19 historical Septembers had lows at or below freezing. However, this has not occurred since 1974. Whereas in the 2010s, three separate years had absolute minima in the 50s, in the 1940s, three separate years saw minima in the 20s. Warmest absolute monthly minima Coldest absolute monthly minima [showing all years at or below the freezing mark] Like central Pennsylvania, many past years had mean monthly minima less than the coldest temperatures observed in recent years. In fact, if we look at 2018's absolute low of 54F at Hagerstown, fully 52 years had mean minima less than or equal to this value in the month of September. And allowing for rounding, fully 57 years had mean mimima less than 54.5F.

With a couple days left in the month, cold air has been lacking in many locations in New England with absolute monthly minima in several locations among the warmest of record. The warmer nights are certainly a blessing for farmers completing their fall harvests. Burlington, Vermont Mount Washington, New Hampshire Caribou, Maine Worcester, Massachusetts Some of these locations have observed several Septembers where the monthly mean low temperature was roughly the same as or colder than 2023's absolute coldest night. Most notably, the year of 1963 saw a mean low at Burlington, Vermont of 40.2F, or nearly 5F colder than 2023's coldest of 45F, and also a mean monthly low of 46.9F at Worcester, Massachusetts, a little more than a degree less than 2023's coldest of 48F. Burlington, Vermont Worcester, Massachusetts

I've been following this for awhile, and it's been interesting to see the dense smoke interacting with the lower sun angles over the high latitudes. Nuuk, Greenland was very dark at midmorning a few days ago, and I saw many in Atlantic Canada observed strange, pale sun through the nearly opaque layer of smoke. Even in the UK, the sun has been significantly dimmed behind the pall of smoke. I wonder if the limited solar radiation will help to promote some early season cold air masses.

Looking at graphs like this, it should be apparent that this is Canada's version of Australia's Black Summer of 2019-2020. Will be interesting to see whether this results in a miniature volcanic winter in the Northern Hemisphere. Smoke from Australia's Black Summer fires are known to have cooled the earth, particularly in the southern hemisphere, and possibly increased the chances of that multi-year La Nina: Smoke from the Black Summer wildfires in Australia impacted climate, high-altitude winds of the Southern Hemisphere (phys.org) A recent study found wildfire smoke and volcanic emissions have offset 20% of the warming which would have otherwise occurred since 2015: Smoke from volcanoes and wildfires have a parallel cooling effect, but it won’t do much to quell global warming | Enterprise Will be interesting to see whether this has any sort of lasting impact on the global, or regional, climate. For the record, there have been a number of intense outbreaks of pyroCb sufficient to loft a significant quantity of soot and smoke into the lower stratosphere over the course of the summer.

Elkins, West Virginia Warmest Absolute Low Temperatures Coldest Monthly Mean Minima Wow!