Posted: 06:45 PM 10/1/12
September 2012 started off very wet with the remnants of Hurricane Isaac moving through central Illinois on the 1st and 2nd. Some places saw nearly 6 inches of rainfall from Friday the 31st through the weekend. This was actually good news, as an extreme drought was hanging on strong that we had dove into in May, June, and July.
The 3rd saw clearing skies, but things were a bit humid in the wake of the tropical system. Tuesday the 4th was a warm and muggy day with a few storms tapping into that humidity in the afternoon. Wednesday saw more widespread thunderstorms that turned severe in the morning. Storm damage was noted in Ramsey, but most places dodged any damage. The storms left us with a less humid Thursday with temperatures around the middle 80s.
The Friday that followed was filled with many rounds of severe storms, none of which that caused any major damage. Behind the storms was clear and cooler weather with highs in the 70s. We'd start a slow climb after that and be back into the 80s by the middle parts of the next week.
Thursday the 13th was also an 80 degree day but a cold front arrived in the evening. Showers followed the front, but only 0.5" of rain was noted. We dropped back into the 70s and a few low 80s for the next 4 days (the 14th - 17th). There was some light rain on the night of the 17th, leaving us with a cooler and breezy Tuesday, the 18th.
The morning of the 19th started with temperatures in the middle to upper 30s, but the sun and a breezy wind from the south warmed things back into the lower 70s. The next day, the 20th, was also warmer as we got into the middle 70s with less wind.
Rain shut off the small warm-up on Friday the 21st with another High School Football night being on the wet side. This made 3 of the first 4 weeks of Friday football wet. The weekend that followed had highs only in the 60s, which is about 10 to 15 degrees below normal.
While Monday the 24th was a sunny day with highs in the 70s, the rest of the work-week wasn't so nice. Rain moved in on the morning of the 25th and it stuck around in a scattered nature until the morning of the 27th. Some heavy rain was noted during this time as well with reports of up to 3" along I-70.
Skies started to clear out on the morning of the 27th with sunshine dominating the afternoon. The 28th started a stretch of mostly sunny to partly cloudy days to end the month with lower to middle 70s for highs.
If you scroll down you'll see some data from the month for local cities.
Illinois was cooler than normal with temperatures averaging at 64.6 degrees, which is 1.6 degrees cooler than normal. If you feel like its been a hot few months, you're right. This was the first cooler than normal month since the previous September. Also, the January-September average was the second warmest on record, just slightly cooler than the 1921 record of 59.7.
Rainfall wise, a much needed above normal month occurred. The statewide average precipitation was 4.9", which is 1.7" above normal. This is the first wetter than normal month this year and broke the drought across central Illinois. For January through September rainfall was the fifth driest on record, less than an inch from the record breaking 1988.
The average temperature for September was 66.3 degrees F, which is 1.5 degrees above the 20th century average. This make this September the 18th warmest on record and the 16th consecutive month with above average temeratures. The precipitation total was 2.40, which is just slightly below the long-term average.
The Ohio Valley was wetter than average for September, mostly because Ohio and Kentucky had top ten wettest. The was mostly because of the reminants of Hurricane Isaac. You can see other national highlights on this map.
The globe set the highest September Temperature on record at 60.21 degreese, which is 1.21 above the average. This was the 36th consecutive September and 331st consecutive month with a global temperature above the average. You can see the hot spots in this map.
You can all of the global highlights in this map.