Sits around the middle of the year.
October in context
How it compares to the rest of the year in Chicago.
Typical rainfall for the year.
Around the yearly average.
Close to the yearly wind average.
Near the middle of the yearly UV range.
One of the less humid months.
Monthly climate breakdown
A detailed look at the typical climate conditions for October.
Thermal profile
Temperature
Typical daytime high
- Nighttime low
-
- Feels like (avg)
-
Light window
Sunshine
11.1 h
Average daylight
- UV index (max)
- 5
- Typical sun hours
- 06:04 - 17:07
Wet-day pattern
Rain & Snow
Typical rainfall
- Rainy days
- 12 days
- Cloud cover (avg)
- 56%
- Snowfall
-
Air feel
Humidity & Wind
70%
Average humidity
- Wind (avg)
-
- Wind (max gusts)
-
Historical daily baseline
Daily climate explorer
Pick a day to inspect the usual conditions through October in Chicago. Based on a 30-year historical climate baseline, not a forecast.
Primary control
Select a day
Scroll to compare daily conditions. The summary updates with your selection.
Secondary context
Monthly trend
Median daytime highs across the month, with a softer low line.
Day 15 selected for October. Temperature 15.6°C.
Historical disruption baseline
Typical disruptions in October
Based on 30 years of historical data, these are the disruption patterns most likely to affect plans in October.
Cold feels-like nights Measures: Cold feels-like nights (min <=5C). Observed about 47% of days (14.6 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
14.6 days / month
- Share of days
- ~47% of days
- Upper edge
- Up to ~5°C (P95)
Why this matters
Cold feels-like nights are possible on ~15 days. Long outdoor blocks become harder to sustain, so layer up and keep a warm indoor fallback nearby.
Rain disruption Measures: Likely rain disruption days. Observed about 17% of days (5.4 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
5.4 days / month
- Share of days
- ~17% of days
- Upper edge
- Up to ~34mm (P95)
Why this matters
Rain disruption risk appears on ~5 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Washout risk Measures: Washout day risk. Observed about 16% of days (5.0 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
5.0 days / month
- Share of days
- ~16% of days
- Upper edge
- Up to ~35mm (P95)
Why this matters
Washout conditions are possible on ~5 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Heavy rain days Measures: Heavy rain days (>=10mm). Observed about 11% of days (3.3 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
3.3 days / month
- Share of days
- ~11% of days
- Upper edge
- Up to ~37mm (P95)
Why this matters
Heavy rain is possible on ~3 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Strong gusts Measures: Strong gust days (>=60 km/h). Observed about 8% of days (2.6 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
2.6 days / month
- Share of days
- ~8% of days
- Upper edge
- Up to ~84km/h (P95)
Why this matters
Strong gusts are possible on ~3 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Stormy conditions Measures: Storm-impact proxy days. Observed about 6% of days (1.8 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
1.8 days / month
- Share of days
- ~6% of days
- Upper edge
- Up to ~82km/h (P95)
Why this matters
Stormy conditions are possible on ~2 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Show all disruptions (23 more)
Washout run Measures: Multi-day washout runs. Observed about 1.3 days/month in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
1.3 days / month
- Share of days
- —
- Upper edge
- Up to ~37mm (P95)
Why this matters
Multi-day washout runs are possible on ~1 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Very heavy rain Measures: Very heavy rain days (>=25mm). Observed about 2% of days (0.5 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.5 days / month
- Share of days
- ~2% of days
- Upper edge
- Up to ~47mm (P95)
Why this matters
Very heavy rain is possible on ~1 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Severe gusts Measures: Severe gust days (>=80 km/h). Observed about 1% of days (0.3 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.3 days / month
- Share of days
- ~1% of days
- Upper edge
- Up to ~89km/h (P95)
Why this matters
Severe gusts are possible on ~0 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Wind disruption Measures: Disruptive wind days. Observed about 1% of days (0.2 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.2 days / month
- Share of days
- ~1% of days
- Upper edge
- Up to ~88km/h (P95)
Why this matters
Disruptive wind is possible on ~0 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Cloudy days Measures: Cloudy days (cloud cover >=60%). Observed about 51% of days (15.8 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
15.8 days / month
- Share of days
- ~51% of days
- Upper edge
- Up to ~100% (P95)
Why this matters
Cloudy skies are possible on ~16 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Gusty days Measures: Gusty days (>=40 km/h). Observed about 50% of days (15.5 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
15.5 days / month
- Share of days
- ~50% of days
- Upper edge
- Up to ~73km/h (P95)
Why this matters
Gusty conditions are possible on ~15 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Wet days Measures: Wet days (>=0.1mm). Observed about 47% of days (14.4 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
14.4 days / month
- Share of days
- ~47% of days
- Upper edge
- Up to ~23mm (P95)
Why this matters
Measurable rain is possible on ~14 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Rainy hours Measures: Rain-hours signal (>=3h rain). Observed about 35% of days (10.7 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
10.7 days / month
- Share of days
- ~35% of days
- Upper edge
- Up to ~20h (P95)
Why this matters
Several rainy hours are possible on ~11 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
Mostly cloudy days Measures: Mostly cloudy days (cloud cover >=80%). Observed about 29% of days (9.1 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
9.1 days / month
- Share of days
- ~29% of days
- Upper edge
- Up to ~100% (P95)
Why this matters
Mostly cloudy skies are possible on ~9 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Wet most of day Measures: Wet-most-of-day signal (>=6h rain). Observed about 25% of days (7.8 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
7.8 days / month
- Share of days
- ~25% of days
- Upper edge
- Up to ~20h (P95)
Why this matters
Wet-most-of-day conditions are possible on ~8 days. Outdoor plans can become unreliable, so keep an indoor backup and flexibility around start times.
High humidity Measures: High humidity days (RH >=80%). Observed about 20% of days (6.1 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
6.1 days / month
- Share of days
- ~20% of days
- Upper edge
- Up to ~92% (P95)
Why this matters
High humidity is possible on ~6 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Cold nights Measures: Cold nights (min <=5C). Observed about 17% of days (5.2 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
5.2 days / month
- Share of days
- ~17% of days
- Upper edge
- Up to ~5°C (P95)
Why this matters
Cold nights are possible on ~5 days. Long outdoor blocks become harder to sustain, so layer up and keep a warm indoor fallback nearby.
Overcast days Measures: Overcast days (cloud cover >=95%). Observed about 14% of days (4.2 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
4.2 days / month
- Share of days
- ~14% of days
- Upper edge
- Up to ~100% (P95)
Why this matters
Overcast skies are possible on ~4 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Cold days Measures: Cold days (max <=10C). Observed about 12% of days (3.9 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
3.9 days / month
- Share of days
- ~12% of days
- Upper edge
- Up to ~10°C (P95)
Why this matters
Cold daytime conditions are possible on ~4 days. Long outdoor blocks become harder to sustain, so layer up and keep a warm indoor fallback nearby.
Breezy days Measures: Breezy days (mean wind >=25 km/h). Observed about 10% of days (3.2 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
3.2 days / month
- Share of days
- ~10% of days
- Upper edge
- Up to ~35km/h (P95)
Why this matters
Breezy conditions are possible on ~3 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Wind chill risk Measures: Wind chill risk days. Observed about 3% of days (1.0 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
1.0 days / month
- Share of days
- ~3% of days
- Upper edge
- Up to ~-1°C (P95)
Why this matters
Wind chill risk is possible on ~1 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Humid days Measures: Humid days (dew point >=18C). Observed about 2% of days (0.5 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.5 days / month
- Share of days
- ~2% of days
- Upper edge
- Up to ~20°C (P95)
Why this matters
Humid conditions are possible on ~1 days. Comfort and pace can drop quickly, so plan shorter outdoor blocks with air-conditioned backup stops.
Cold snap run Measures: Cold snap runs (>=3 cold days). Observed about 0.5 days/month in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.5 days / month
- Share of days
- —
- Upper edge
- Up to ~10°C (P95)
Why this matters
Cold snap runs are possible on ~1 days. Long outdoor blocks become harder to sustain, so layer up and keep a warm indoor fallback nearby.
Fog-likely signal Measures: Fog-likely visibility proxy. Observed about 1% of days (0.3 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.3 days / month
- Share of days
- ~1% of days
- Upper edge
- Up to ~93% (P95)
Why this matters
Fog-likely conditions are possible on ~0 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Low visibility proxy: same as fog-likely (RH ≥90% AND cloud ≥95%) — true visibility requires hourly visibility data Measures: Low visibility proxy: same as fog-likely (RH ≥90% AND cloud ≥95%) — true visibility requires hourly visibility data. Observed about 1% of days (0.3 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.3 days / month
- Share of days
- ~1% of days
- Upper edge
- Up to ~93 (P95)
Why this matters
Low visibility proxy: same as fog-likely (RH ≥90% AND cloud ≥95%) — true visibility requires hourly visibility data is possible on ~0 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Snow days Measures: Snow days (>=0.1mm snowfall). Observed about 1% of days (0.3 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.3 days / month
- Share of days
- ~1% of days
- Upper edge
- Up to ~6.0mm (P95)
Why this matters
Snowfall is possible on ~0 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Freezing nights Measures: Freezing nights (min <=0C). Observed about 1% of days (0.2 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.2 days / month
- Share of days
- ~1% of days
- Upper edge
- Up to ~-0°C (P95)
Why this matters
Freezing nights are possible on ~0 days. Fixed-time outdoor plans are safer with a backup option and flexible timing.
Windy days Measures: Windy days (mean wind >=35 km/h). Observed about 1% of days (0.2 days/month) in October. Historical risk signal only, not a day-by-day forecast.
Likely frequency
0.2 days / month
- Share of days
- ~1% of days
- Upper edge
- Up to ~40km/h (P95)
Why this matters
Strong mean winds are possible on ~0 days. Exposed activities and transport links are more likely to be disrupted, so keep sheltered alternatives ready.
Travel planning FAQ
Frequently asked questions
Quick answers to the weather questions you ask the most.
Is October a good time to visit Chicago?
Typical October days in Chicago reach highs of 16°C (61°F) with nights around 9°C (48°F). It usually feels mild by day and cool after dark. Overall, October sits in the middle of the Chicago climate range.
What are temperatures like in October?
Daytime temperatures in October typically peak near 16°C (61°F), while nights drop to around 9°C (48°F). Expect mild afternoons and cool evenings.
How much does it rain in October?
Rainfall in October averages 91 mm (3.6 in) across roughly 12 days. Overall it is a quite rainy time of year, so a light rain jacket and waterproof shoes are very handy.
How many hours of daylight are there in October?
You can expect about 11 hours of daylight in October. Sunrise is typically around 06:04 and sunset near 17:07. Daylight is fairly typical, with enough time for sightseeing.
How strong is the sun in October?
UV levels are moderate (around 5); sunscreen and sunglasses are still a good idea.
Is it windy in October?
In October, average wind speeds are around 17 km/h (11 mph), with gusts on the windiest days reaching about 58 km/h (36 mph). On the ground, it is it can feel quite windy at times, particularly when weather systems move through.