The book comes to a close on the month of October. A month of transition, where we see sunset times shrink from after 6:30 on October 1st, to well before the clock hits 6:00 by Halloween. The average temperature falls from a refreshing 60° down to a chilly 48° along the course of our 31-day journey. And October 2017, while doing it in strangely uniform fashion, did follow that overall cooling trend. A month that gave us both what was almost certainly our last 80-degree day, as well as our first snowflakes of the season.
Without taking a look at the numbers, it certainly felt like a solid months worth of classic autumn weather. In reality, the month comes to a close 4 degrees warmer than average, with nearly twice the typical precipitation. I said October followed the expected cooling trend from October 1st to the 31st, but let's take a closer look at the dramatic fashion in which it did so here in C-U. 22 of the first 23 days in October were either average, or warmer than average. Only one day in the first three weeks was cooler than average! The weather pattern wasn't just slightly warmer than what's typical this time of year either – half of those 22 days were at least 10-degrees warmer than average. But to my annual disappointment, summer always comes to an eventual end. Mother Nature is constantly working to create a balance - and we followed up nearly three straight weeks of uninterrupted warmth by finishing October on a streak of 8 consecutive colder-than-average days. We even saw our first snowflakes on the 28th!
We saw measurable precipitation on 16 out of the 31 days in October, for a monthly total of 6.31”. A typical October sees about 3.26” of rain. After a very dry summer which found portions of Champaign County in a moderate drought, this excess rainfall was certainly welcome, even if it did keep harvest-ready farmers out of their fields at times. No portion of Champaign County currently remains included in a moderate drought, and only the southeastern portion of the county (think Homer, Sidney, Broadlands) is included in an area outlined as abnormally dry.
As we began the month of October here in Champaign-Urbana, we experienced high temperatures in the 70s and 80s for the first 10 days. Along with the warmer start, we also found much of that excess rain falling in the first half of the month. Rain began falling on October 4th, and did not stop again until the 14th. It certainly wasn't uninterrupted, but you follow the general point that for ten consecutive days we saw measurable rainfall in C-U. For good measure, after taking the day off on the 14th, it rained again on the 15th and 16th.
After continuing to be warm with high temperatures generally in the 70s, the bottom finally fell out on October 23rd. We have only seen one day reach above 60° since that point while experiencing our first frost, and temperatures below the freezing mark as lows hit 31° on the 29th, and 30° the morning of Halloween.
So where are we headed in November? Well, as of my writing this, things actually look fairly warm to start the month. The first week of November could hold several days with high temperatures in the 60's, perhaps even closing in on 70° with spring-like thunderstorms in the forecast. The long-range forecast for the remainder of November calls for near-average temperatures, with above average precipitation. Nothing is guaranteed in long-range forecasting, but I'd look for another heavy rain event or two this month, with perhaps our first measurable snowfall coming in the last week or two of November. Again, I'm not sealing anything here with a promise, but it would surprise me if we weren't talking about at least one minor accumulating snow event by the time we're closing the books on November. See you all on the other side!
Andrew Pritchard runs Chambana Weather, and you can hear his weather forecasts daily on WILL-AM/FM, WEFT-FM, and WPCD-FM.
Champaign-Urbana monthly climate data is courtesy of the Illinois State Water Survey.