Chicago
October fared warmer than normal with the average monthly temperature 57.1°F (3.1° above normal). Precipitation, on the other hand, fell short of typical amounts, with 2.28” recorded (normal 3.43”). The month also featured the first snowfall for the season with 0.9” of snow (higher than the typical 0.2” seen in October).
The month started off with temperatures that made it feel much more like July than early autumn. Daytime highs reached into the high 80s through the first several days, with the 1st and 3rd tied for the warmest days of the month at 87°F. Following a duration of quiet weather that coincided with the heat, showers and storms returned the 4th through the 6th, bringing with it a break from unseasonable warmth. In the span of two days, highs tumbled from 84° to 62°F.
Quieter, albeit cooler conditions returned on the 7th through the 10th, during which time the first frost of the season occurred on the 10th. An unsettled pattern returned on the 11th bringing with it periods of storms and steady rain that continued intermittently through the 15th. The 14th was the wettest day of the month, recording 0.57” of rainfall. Following a brief break from the rain, showers returned to the region on the 18th with storms making a return the next day.
Warmer temperatures made a notable return during the final third of the month, with highs pushing into the 80s for a time after the 23rd. Daytime highs on the 24th reached 83°F, tying the date’s previous record that had been set in 1963. This warm spell was brief, with temperatures trending cooler through the remainder of the month. Showers returned on the 25th with additional showers around through the 27th (with only minor showers again on the 29th).
The first recorded snowfall of the season occurred on Halloween with a coating - 1 inch of accumulation in most spots. However, some places near the IL/WI border topped out around 2" of snow. With gusty winds in the storm's wake, even some blowing snow occurred!
Light snowfall outside of the NWS Chicago office. Courtesy of NWS Chicago.
Indianapolis
Warmer weather at the start of October helped push monthly averages above normal with Indianapolis recording 57.5°F (2° warmer than normal). Precipitation fell short of normal, with 2.47” of rainfall, well below the 3.22” average. Early-season snow was not that far off from what is typically seen in October, with a trace (non-measurable) amount of snow reported, whereas the area typically sees 0.2” of snow.
Summer-like temperatures were around for the first few days of October as highs soared into the 80s with dry conditions. The warmest day of the month, the 3rd, managed to see highs top out at 86°F. A system moving through the region on the 5th brought an end to this unseasonable warmth, reducing highs to the 50s and 60s in the days that followed. The 5th managed to pick up the most rainfall of the month with 0.78”.
Drier conditions returned for a time as temperatures trended warmer. By the 12th and 13th, temperatures had returned to the mid 70s. The 13th produced some storms with showers persisting throughout the following days, at which point temperatures had settled back into the 50s and 60s.
Following a few showers the 19th and 20th, drier weather returned with another warming period. Pleasant conditions with highs in the 70s continued into the 24th.
Unsettled weather returned on the 25th and lingered through the remainder of the month. Initially, scattered showers moved through on the 25th - 27th with a more organized system and steady rain on the 28th, dropping highs into the 50s. A quick-moving system on Halloween brought with it a few snow showers and flurries. While only some scattered coatings occurred in and around Indianpolis, a few tenths of snowfall were reported north of the city towards Noblesville.
3-Day Rainfall across Indiana from October 27th - 30th. Courtesy of NWS Indianapolis.
Ohio
Like other areas in the Midwest, Ohio trended warmer this October. Columbus had an average temperature of 57.6°F (2.4° warmer than normal) and Cincinnati averaged 57.2°F (1° warmer than normal). Precipitation totals exceeded the norm, with Columbus measuring 3.11” (normal 2.90”) and Cincinnati measuring 3.72” (normal 3.35”). Both cities saw snow (albeit unmeasurable), which was below the normal 0.2” typically seen in October.
Unseasonably warm temperatures ushered in the start of October, with it feeling more like mid-summer, highs consistently topped the 80-degree mark. The 3rd was the hottest day of the month for both Columbus and Cincinnati, which topped off at 87° and 86°F, respectively. Conditions remained dry during this time as well.
The warmth came to an end with the arrival of some showers on the 5th and 6th, with daytime highs falling back into the 50s and 60s. After a showery several days, conditions quieted down with temperatures trending mild once more the 12th and 13th. Cincinnati managed to reach 80°F on the 12th.
The middle of the month featured periods of rain at times with dry breaks in-between. A system on the 14th and 15th broke the returning warm trend and settled temperatures back into a more seasonable level. Another period of rain developed the 19th and 20th, with the former date being the wettest day of the month in Columbus with 0.72” of rain.
Once showers moved out, Ohio saw a decent stretch of drier conditions that lasted well into the final week of the month. With these pleasant days came a return of the warmth with highs creeping into the mid 70s.
Unsettled weather returned to close out the month, with a system moving in on the 27th that brought decent periods of rainfall to the region through the 30th. During this time, Cincinnati saw their wettest day of the month, reporting 0.91” of rain on the 28th. The passage of this system brought an end to the warmth as highs slipped into the 50s and later the 40s. Halloween featured the first snowfall of the season in the form of snow showers. Most places from Cincinnati to Dayton and Columbus only saw scattered coatings, but a few towns north of I-70 did manage to accumulate a few tenths of snowfall.
