The statewide average temperature for August so far is 72 degrees, 2 degrees below average. This follows on the heels of the cool July. The NWS forecast show that the mild temperatures will continue this upcoming week with highs in the upper 70s and low 80s in northern Illinois to the low to mid 80s in central and southern Illinois. The 6-10 and 8-14 day forecasts that extend out to August 21 point towards a continuation of cooler-than-average conditions.
All in all, it should be great weather for the Illinois State Fair. I can remember many years of the State Fair being hot and humid with your choice of either dust or mud. It’s a wonder the butter cow did not melt.
The map of observed precipitation below from the NWS shows that rainfall has been widespread and fairly heavy in western and southern Illinois with amounts ranging from 1 inch (green) to 5 inches (red). It is lighter and more variable in northern and eastern Illinois, ranging from 0.1 inches (light blue) to 2 inches (dark green). Much of that heavy rain to the east of St. Louis fell in a part of Illinois that was dry in July.
Data from satellite sensors show that during the Northern Hemisphere’s growing season, the Midwest region of the United States boasts more photosynthetic activity than any other spot on Earth, according to NASA and university scientists.
They determined this by measuring the fluorescent glow that healthy plants give off when they grow. It is not visible to the human eye but can be picked up by special sensors on satellites. The press release has a lot more details.
If you click on the map, you can see the full version. While they don’t have any state boundaries, you can make out Lake Michigan. Based on that, it looks like one of the brightest areas is across central and northern Illinois – no surprise there.
The Illinois State Water Survey maintains a network of 19 soil temperature sites across the state that measure temperatures at 4 and 8 inches. You can look at maps for 10 am, any hour of the day, high for the day, low for the day, under sod, and under bare soil. You can find all their data at this site: http://www.isws.illinois.edu/warm/soiltemp.asp
Here is the 4-inch soil temperature from yesterday. It’s always a day behind so that they can upload the data and do quality control checks. The data now arrive hourly. My mistake – they used to upload the data once a day and do QC but now it is more timely. As you would expect, soil temperatures change more slowly than the air temperatures.
And here is what it looked like two years ago after a record warm March. I chose April 2, 2012 for the same time of day and depth. As you can see, the soil temperatures were about 12 degrees warmer and USDA NASS reported that 5% of the corn crop had already been planted by that date.
We have had a remarkable contrast in the last two winters in terms of precipitation. While both winters have been relatively quiet in terms of snow (at least up until the last week), this winter has made up for it in rainfall.
Here are the January 1 to February 25 precipitation departure maps for 2012 (first figure) and 2013 (second figure) for the Midwest. Precipitation is the combination of rainfall and the water content of any snow/sleet/freezing rain events.
Areas in shades of yellow show below-average precipitation while areas in shades of green show above-average precipitation. As you can see, the widespread yellow in 2012 was replaced with widespread green in 2013. This is good news for Illinois and for the Midwest.