66
Winter
Best afternoon
Winter in Chicago averages a 66 Run Score (Good); the kindest window is typically afternoon, with temperatures around -1°C and comfortable dew points.
Chicago · United States
Best Time to Run in Chicago Today
Lakefront wind is the wildcard. A 5°F day and a 25 mph gust are two different runs at the same temperature. Check below for a live Run Score, the best window today, and the pace adjustment the conditions call for.
Chicago running weather workbenchTemperature · dew point · wind · timing
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Typical running conditions in Chicago
Across a typical year, the best running weather in Chicago lands in May, when daytime Run Scores average 81 (Great). The hardest stretch is July, with temperatures around 73°F (23°C) and noticeable dew points near 64°F. The stickiest month is July (dew point 64°F). Year-round, Chicago averages a 72 Run Score. Everything below is the typical pattern by month and by hour of day, scored with the same engine as the live calculator above — so you can plan the season and the time of day, not just today.
Best time to run in Chicago, by season
When the kindest window falls shifts with the season. Typical Run Score and the best time of day for each.
76
Spring
Best midday
Spring in Chicago averages a 76 Run Score (Good); the kindest window is typically midday, with temperatures around 10°C and comfortable dew points.
69
Summer
Best early morning
Summer in Chicago averages a 69 Run Score (Good); the kindest window is typically early morning, with temperatures around 22°C and noticeable dew points.
78
Autumn
Best early morning
Autumn in Chicago averages a 78 Run Score (Good); the kindest window is typically early morning, with temperatures around 13°C and comfortable dew points.
Chicago running weather, month by month
Typical temperature, dew point, and Run Score for each month — plus the best window of the day. Based on 2022–2024 history.
| Month | Avg temp | Dew point | Typical Run Score | Best window |
|---|---|---|---|---|
| January | 26°F (Cold) | 19°F (Comfortable) | 61 Mixed | 7 AM–11 PM |
| February | 32°F (Cold) | 23°F (Comfortable) | 68 Good | 11 AM–7 PM |
| March | 39°F (Cold) | 30°F (Comfortable) | 73 Good | 8 AM–11 PM |
| April | 49°F (Cool) | 39°F (Comfortable) | 75 Good | 6–10 AM |
| May | 60°F (Warm) | 51°F (Comfortable) | 81 Great | 6–11 AM |
| June | 70°F (Warm) | 57°F (Pleasant) | 71 Good | 6–8 AM |
| July | 73°F (Warm) | 64°F (Noticeable) | 67 Good | 6–9 AM |
| August | 72°F (Warm) | 64°F (Noticeable) | 68 Good | 6–9 AM |
| September | 67°F (Warm) | 58°F (Pleasant) | 76 Good | 6–10 AM |
| October | 55°F (Ideal) | 44°F (Comfortable) | 79 Good | 6 AM–12 PM |
| November | 43°F (Cool) | 35°F (Comfortable) | 79 Good | 6 AM–11 PM |
| December | 33°F (Cold) | 26°F (Comfortable) | 68 Good | 9 AM–11 PM |
Dew point is the real story in Chicago
Dew point — not the thermometer — decides how hard a run feels. The muggiest month in Chicago is July, when the typical dew point reaches 64°F (18°C) (noticeable). At that point sweat stops evaporating efficiently, so even a moderate temperature feels brutal. Compare that with May, the easiest month, when dew points sit near 51°F and the same effort feels far lighter. The hour-by-hour scores above already fold this in.
Running in Chicago, month by month
Typical conditions and the best time to run for each month of the year.
What the calculator scores
The Run Score is not a single reading dressed up. Eight weather signals are weighted by how much each one actually changes a run, then combined into one decision.
Temperature
Performance peaks near 50–54°F. Every degree above that taxes your cooling system and slows the pace you can hold at the same effort.
Dew point
The real humidity signal. Above ~60°F dew point, sweat stops evaporating efficiently — the single biggest hidden driver of a hard summer run.
Wind
Headwinds cost pace and gusts break rhythm. The model weighs sustained speed and direction, not just the headline number.
Heat stress
How hard heat, humidity, sun, and wind hit your body, combined into one number (wet-bulb globe temperature) — the same metric race directors use to flag risk.
Solar exposure
Direct radiation on a shadeless route can feel far hotter than the air temperature. Cloud cover and sun angle are factored in.
Precipitation
Rain probability and intensity affect footing, comfort, and gear — weighted by how likely it is during your window.
Air quality
US AQI is folded in so sensitive runners get a clear signal when particulates make hard efforts a bad idea.
Pace adjustment
The output you actually use: how many seconds per mile to give back today so your effort — not the clock — stays honest.
How it works
01
Enter your city
Search any city worldwide. RunWeather pulls the live local forecast — temperature, dew point, wind, sun, and air quality.
02
Get a 0–100 Run Score
One number that blends performance, safety, and experience — labeled Perfect, Great, Good, Mixed, or Poor — for the current hour.
03
Scrub the next 12 hours
Tap any hour to rebuild the full breakdown for that start time, or jump straight to the best window today.
Running weather in nearby cities
Same engine, different climate. Check the best time to run in these cities too.
Running in Chicago: FAQ
What's the best month to run in Chicago?
May. Typical daytime Run Scores average 81 (Great), the best of the year, with temperatures around 60°F (16°C).
When is it too hot to run in Chicago?
July is the toughest month — typical temperatures near 73°F (23°C) with noticeable dew points around 64°F. On days like that, run in the 6–9 AM window and ease off the pace.
What time of day is best for running in Chicago?
In the warm months the kindest window is typically early morning. Across the year the highest-scoring hours cluster early; the month-by-month table above lists the best window for each month.
When is the best time to run in Chicago?
It depends on the day. Lakefront wind is the wildcard. A 5°F day and a 25 mph gust are two different runs at the same temperature. Run the calculator above and it returns today's highest-scoring window for Chicago — usually early morning or evening when heat and dew point are lowest. Tap any hour to see the full breakdown.
What is a good Run Score?
Scores run 0–100. 97+ is Perfect, 80–96 is Great — conditions are actively working in your favour. 65–79 (Good) is solid. 45–64 (Mixed) means at least one factor — usually heat or dew point — is taxing you. Below 45 (Poor), expect a noticeably harder effort or hold back for safety.
Why does dew point matter more than temperature?
Your body cools by evaporating sweat. When the dew point climbs above roughly 60°F, the air is too saturated for sweat to evaporate efficiently, so heat builds up even if the thermometer looks reasonable. That's why a 70°F muggy morning can feel harder than a dry 80°F afternoon.
How is this different from a normal weather app?
A weather app tells you the conditions. This calculator translates them into a running decision: a single score, the best hour to head out, and a concrete pace adjustment in seconds per mile — using the same scoring engine that powers the RunWeather app.
Is the running weather calculator free?
Yes. The calculator is completely free to use, with no account required. The RunWeather app adds Strava sync, multi-day planning, and personalized heat acclimation on top of the same model.
Get this on every run, automatically
RunWeather syncs with Strava, plans your week, and learns your heat tolerance — so the right time to run finds you.