September was a Little Cooler and Drier than Average

Bill’s Blog

Posted: Oct 2, 2020 / 01:54 AM EDT Updated: Oct 2, 2020 / 02:04 AM EDT

September 2020 Climate Summary

September was a little cooler and drier than average. Grand Rapids had an average temperature of 61.5° and that was 1.2° cooler than average. The highest temperature was 85° on the 3rd and the coolest was 36° on the 19th. The last four Septembers were 3.5°, 3.3°, 3.7° and 3.6° warmer than average, so this September was 4.5° to 4.9° cooler than recent Septembers.

Fall colors in the U.P south of Marquette – from Patrick DeHaan

The fall color change is about a week earlier than last year. You can see peak or close to peak color now over much of Upper Michigan.

Lake Superior satellite picture

We haven’t had a lot of clear-partly cloudy days of late, but this satellite picture from 9/23 shows some reddish color across the U.P. where the fall color can actually be seen from outer space.

Gun Lake Sunrise

Here’s a pretty sunrise a week and a half ago at Gun Lake. Smoke from Western wildfires turned our sky a milky white for a few days instead of bright blue. Rainfall for the month was 3.07″ in G.R. and that was 1.21′ below average. For the year, G.R. is only 0.81″ above average. We had a stretch of 18 days from the 10th through the 27th when only 0.08″ of rain was recorded. We only had 3 days with thundershowers and G.R. did not have any heavy (1/4 mile visibility) fog during the month.

Everett flying his kite at the Gun Lake Beach

This is Everett. I met him and his parents at the Gun Lake Beach. There were several kites there – a great place to fly a kite with a steady wind coming off the lake. The average wind speed for September was 8.7 mph and the fastest gust was 46 mph on the 3rd.

Just before sunset at the Gun Lake Beach

G.R. had 59% of possible sunshine in September. If you take June (a record 82%), July (75%), August (73%) and September (59%), Grand Rapids had 72% sunshine for those four months. With a little above average temperatures, above average sunshine, and less than average severe weather, I think most people would call this a good summer (weatherwise).

Sea Surface Temperature Anomaly

This is global sea surface temperature difference from average. You’ll note that much of the globe has above average water temperatures, including much of the water around North America. You can also see the “La Nina” – the cooler than average water along the Equator in the Pacific Ocean. That is caused by faster than average wind, which brings up colder water from beneath the surface.

This is a common La Nina winter pattern

The above map shows a common La Nina winter pattern. We’re not ready to make a winter forecast, but the pattern above shows dry weather in the Southern U.S., warmer than average conditions on the East Coast, wet weather in the Pacific NW and Ohio Valley and cold from Alaska to the northern High Plains. La Nina is one of many factors that influence our prevailing winter weather pattern.