The trend is colder by almost 2 degrees F for lowest minimum temperature over 129 years at KGRR.
This chart shows, like the charts for heating degree days or average temperature discussed earlier, the boat anchor for temperature which is 1943-1997. The anchor is heavy enough to keep the mean minimum since 1963 lower than before it, at -9F vs. -6F, despite all the recent warming.
Mean lowest minimum temperature:
1896-1943: -5F (48yrs)
1943-1997: -10F (55yrs)
1997-2024 to date: -5F (28yrs).
The mean for annual heating degree days has dropped about 63 HDD from 1904-1963 at 6726 shown, to 6663 for 1963-2023, or 0.94%.
In the last 23 years, just 5 have been at or above the old mean shown, while 18 have been below. In the previous 23 years the pattern was much more even: 13 above the old mean shown and 10 below.
This is clearly a picture of recent moderating winters, but people forget that this comes on the heels of a prolonged period of much more severe winter cold extending 55 years from 1943-1997. During that period there were 40 winters above the old mean shown, and just 15 below it.
That cold period itself followed upon a previous period of previously well known warming where about 58% of the seasons in the record saw heating demand well below the old mean.
The Dust Bowl era. Maybe you've heard of it.
Higher mean heating degree day totals in the second half of the 20th century indicate its colder conditions compared with the eras book-ending it:
1904-1943: 6685 (40yrs)
1943-1997: 6883 (55yrs)
1997-2023: 6351 (27yrs).
The mean has risen 0.1 degrees F 1898-1963 at 48.2 shown, to 48.3 1963-2023, which is 0.2%.
The uptrend traverses about 0.9 degrees F over 125 years.
Planet's on FIRE lol.
Could easily be just heat island effect. The mean for average temperature is definitely warmer since 1997:
1997-2023: 49.4 (27yrs)
1943-1997: 47.5 (55yrs)
1898-1943: 48.4 (46yrs).
The relatively colder second half of the 20th century remains the noteworthy anchor of this graph's center.
Wetter!
The long term trend for the Oceanic Nino Index is thought to be predictive of this wetter outcome in the Upper Midwest. The index trend is cooler from about +1 degree F anomaly to -1 degree F anomaly since 1951.
Mean annual precipitation at KGRR has risen from 31.88 inches 1903-1951 to 36.81 inches 1951-2023.
Tuesday’s global average temperature was calculated by a model . . . to estimate daily average temperatures starting in 1979.
“This is our ‘best guess’ of what the surface temperature at each point on earth was yesterday,” [Paolo Ceppi] said.
WaPo, of course.
Meanwhile, back in the real world of actual measurement, the highest maximum at KGRR so far in 2023 was 91 degrees F, on three days in June.
And the hottest 4th of July was way back in 1911. Yesterday made it to 89.
Maximum temperature observed has been in decline here for decades.
Could be just a heat island effect from KGRR.
Through 2021 mean precipitation for the eight months Jan-Aug is 22.88, but for Jan-Aug 2022 we've got 27.61 inches.
Wet. Wet. Wet.
Meanwhile out West it's the reverse.
Dry. Dry. Dry.
The trend line after 123 years of data shows average temperature in Grand Rapids, Michigan, rising 0.7 degrees F, or 0.388 degrees C, 65% less than the 1.1 degrees C claimed for the world by the United Nations Intergovernmental Panel on Climate Change yesterday.
And the minimal warming in Grand Rapids may in fact be misleading. Five of the data points in those top eight are from the last twenty-five years, during which increasing development around the KGRR measuring station may well be contributing heat island effects.
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