Chicago O'Hare Temperature Market Guide
KORD • Chicago O'Hare International Airport
Polymarket
Chicago O'Hare International Airport (KORD) provides an alternative Chicago temperature market distinct from Midway (KMDW). Located northwest of downtown, O'Hare experiences slightly different microclimates due to its position further from Lake Michigan and its massive concrete infrastructure creating localized heat island effects.
Quick Facts
| Station Code | KORD |
|---|---|
| Location | Chicago (O'Hare), IL |
| Coordinates | 41.9602°N, 87.9316°W |
| Elevation | 672 ft (205 m) |
| Timezone | CT (America/Chicago) |
| NWS Office | LOT - Chicago |
| Resolution Source | NWS CLI Report ↗ |
About KORD Weather Station
O'Hare International Airport (KORD) is one of the busiest airports in the world and serves as a key weather observation point for the Chicago metropolitan area. Located about 14 miles northwest of downtown Chicago, the station sits at 672 feet elevation.
Unlike Midway Airport (KMDW), O'Hare is positioned further inland from Lake Michigan, which can result in slightly different temperature readings, particularly during lake breeze events in spring and summer. The station's location amid extensive runways and terminals creates a notable urban heat island effect.
KORD uses standard ASOS equipment with temperature reported in whole degrees Fahrenheit after conversion from Celsius readings.
Unlike Midway Airport (KMDW), O'Hare is positioned further inland from Lake Michigan, which can result in slightly different temperature readings, particularly during lake breeze events in spring and summer. The station's location amid extensive runways and terminals creates a notable urban heat island effect.
KORD uses standard ASOS equipment with temperature reported in whole degrees Fahrenheit after conversion from Celsius readings.
Climate Patterns
Chicago O'Hare shares the continental climate of the greater Chicago area (Koppen: Dfa), characterized by cold, snowy winters and warm, humid summers. However, its inland position means less direct Lake Michigan moderation compared to lakefront stations.
Summer highs typically reach the mid-80s°F, occasionally pushing into the 90s during heat waves. The concrete expanse of the airport can amplify daytime heating. Winter brings frequent Arctic air intrusions with highs sometimes failing to reach 20°F.
The spring and fall transition seasons are highly variable, with rapid temperature swings common as air masses battle for dominance over the region.
Summer highs typically reach the mid-80s°F, occasionally pushing into the 90s during heat waves. The concrete expanse of the airport can amplify daytime heating. Winter brings frequent Arctic air intrusions with highs sometimes failing to reach 20°F.
The spring and fall transition seasons are highly variable, with rapid temperature swings common as air masses battle for dominance over the region.
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Open Live DashboardSeasonal Trading Considerations
Winter (December - February): Cold and variable with highs ranging from teens to 40s°F. Arctic outbreaks can bring dangerous cold. Lake-effect snow typically misses O'Hare but watch for clipper systems.
Spring (March - May): Highly variable as winter reluctantly yields. Temperature swings of 30-40°F within a week are common. Lake breeze effects are weaker at O'Hare than at lakefront locations.
Summer (June - August): Warm to hot with highs in the 80s and 90s°F. Heat waves can push temperatures near 100°F. Afternoon thunderstorms can rapidly cool temperatures.
Fall (September - November): Gradual cooling with pleasant conditions. First frost typically arrives in October. Increasing cloudiness as the season progresses.
Spring (March - May): Highly variable as winter reluctantly yields. Temperature swings of 30-40°F within a week are common. Lake breeze effects are weaker at O'Hare than at lakefront locations.
Summer (June - August): Warm to hot with highs in the 80s and 90s°F. Heat waves can push temperatures near 100°F. Afternoon thunderstorms can rapidly cool temperatures.
Fall (September - November): Gradual cooling with pleasant conditions. First frost typically arrives in October. Increasing cloudiness as the season progresses.
Trading Tips for Chicago O'Hare
Compare O'Hare forecasts with Midway (KMDW) when both markets are available. O'Hare typically runs 1-3°F warmer in summer due to its urban heat island and slightly cooler in winter during lake-moderated events.
The lake breeze is less impactful at O'Hare than at locations closer to Lake Michigan. On summer days when the lake breeze keeps lakefront temperatures in the 70s, O'Hare may still reach the mid-80s.
Watch for temperature inversions during winter high pressure events. O'Hare's suburban location can trap cold air, while locations closer to the lake or downtown may be slightly warmer.
Thunderstorm timing is critical in summer. Check radar trends - storms moving through during peak heating hours (2-5 PM) can prevent the high from being reached.
The lake breeze is less impactful at O'Hare than at locations closer to Lake Michigan. On summer days when the lake breeze keeps lakefront temperatures in the 70s, O'Hare may still reach the mid-80s.
Watch for temperature inversions during winter high pressure events. O'Hare's suburban location can trap cold air, while locations closer to the lake or downtown may be slightly warmer.
Thunderstorm timing is critical in summer. Check radar trends - storms moving through during peak heating hours (2-5 PM) can prevent the high from being reached.
Market Resolution Details
Chicago O'Hare temperature markets resolve using the official daily high temperature recorded at KORD as published in the NWS CLI (Climatological Data) report. The CLI report is issued by the NWS Chicago (LOT) forecast office.
The daily maximum temperature observation runs from midnight to midnight local time (Central Time).
View the latest KORD CLI Report →
The daily maximum temperature observation runs from midnight to midnight local time (Central Time).
View the latest KORD CLI Report →
Data Release Schedule
Typical release times for key data products at KORD. Times shown in UTC.
| Data Type | Typical Time (UTC) | Variability |
|---|---|---|
| CLI Report Daily climatological summary |
06:37 UTC | ±5 min |
| 24hr High METAR with max temp |
05:51 UTC | ±1 min |
| METAR Hourly observations |
Hourly at :51 | ±1 min |
| DSM #1 Daily summary message |
22:17 UTC | Issuance time |
| DSM #2 Daily summary message |
21:17 UTC | Issuance time |
| DSM #3 Daily summary message |
23:17 UTC | Issuance time |
| DSM #4 Daily summary message |
21:16 UTC | Issuance time |
6-Hour High/Low Reports
These METARs include 6-hour maximum and minimum temperatures, useful for tracking intraday temperature trends.
05:51 UTC
11:51 UTC
17:51 UTC
23:51 UTC
Note: Times are approximate and may vary. CLI reports are the official resolution source for temperature markets. See NWS Data Guide for more information.
Data Resources
Quick links to official data sources and tools for Chicago (O'Hare).
📊 NWS Data
🗄️ Iowa Environmental Mesonet
📈 Wethr.net Tools
Forecasting Challenges
Lake Breeze Boundary: The position of the lake breeze front on summer days determines whether O'Hare stays warm or cools significantly. This boundary can be difficult to predict precisely.
Urban Heat Island: The massive airport complex creates its own microclimate, making O'Hare often warmer than surrounding suburban areas.
Convective Timing: Summer thunderstorms develop rapidly over the Chicago area. Storm timing relative to peak heating determines whether forecast highs verify.
Arctic Air Modification: In winter, the degree to which Arctic air masses moderate as they cross the relatively warm lake affects how cold O'Hare gets.
Urban Heat Island: The massive airport complex creates its own microclimate, making O'Hare often warmer than surrounding suburban areas.
Convective Timing: Summer thunderstorms develop rapidly over the Chicago area. Storm timing relative to peak heating determines whether forecast highs verify.
Arctic Air Modification: In winter, the degree to which Arctic air masses moderate as they cross the relatively warm lake affects how cold O'Hare gets.
Historical Temperature Records
Record High: 105°F recorded on July 24, 1934.
Record Low: -27°F recorded on January 20, 1985.
Historical Note: O'Hare has been an official observation site since 1958. Its records reflect the broader Chicago climate while capturing the unique microclimate of this major airport facility.
Record Low: -27°F recorded on January 20, 1985.
Historical Note: O'Hare has been an official observation site since 1958. Its records reflect the broader Chicago climate while capturing the unique microclimate of this major airport facility.
📡 Official Data Sources
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