KORD — CHICAGO O'HARE
Chicago O'Hare, IL, US · America/Chicago · 41.9602°, -87.9316° · 200m elevation
Daily METAR Observations
| Time | Temperature | Dew Point | Humidity | Wind | Wind Speed | Wind Gust | Pressure | Precip. | Condition |
|---|---|---|---|---|---|---|---|---|---|
| 12:51 AM | 68 °F 68 °F 20 °C 20 °C | 58 °F 57.9 °F 14 °C 14.4 °C | 70 % | SW | 6 mph 5 kt 9 km/h | 0 mph 0 kt 0 km/h | 29.95 in | 0.0 in | Fair |
| METAR KORD 130551Z 22005KT 10SM CLR 20/14 A2995 RMK AO2 SLP136 T02000144 10267 20200 402720161 50006 $ | |||||||||
| 1:51 AM | 66 °F 66 °F 19 °C 18.9 °C | 58 °F 57.9 °F 14 °C 14.4 °C | 75 % | SSW | 6 mph 5 kt 9 km/h | 0 mph 0 kt 0 km/h | 29.93 in | 0.0 in | Fair |
| METAR KORD 130651Z 20005KT 10SM CLR 19/14 A2993 RMK AO2 SLP132 T01890144 $ | |||||||||
| 2:51 AM | 66 °F 66 °F 19 °C 18.9 °C | 58 °F 57.9 °F 14 °C 14.4 °C | 75 % | SSW | 7 mph 6 kt 11 km/h | 0 mph 0 kt 0 km/h | 29.93 in | 0.0 in | Fair |
| METAR KORD 130751Z 21006KT 10SM CLR 19/14 A2993 RMK AO2 SLP130 T01890144 $ | |||||||||
| 3:51 AM | 65 °F 64.9 °F 18 °C 18.3 °C | 58 °F 57.9 °F 14 °C 14.4 °C | 78 % | SSW | 7 mph 6 kt 11 km/h | 0 mph 0 kt 0 km/h | 29.93 in | 0.0 in | Fair |
| METAR KORD 130851Z 21006KT 10SM CLR 18/14 A2993 RMK AO2 SLP130 T01830144 55006 $ | |||||||||
| 4:51 AM | 65 °F 64.9 °F 18 °C 18.3 °C | 58 °F 57.9 °F 14 °C 14.4 °C | 78 % | SSW | 8 mph 7 kt 13 km/h | 0 mph 0 kt 0 km/h | 29.94 in | 0.0 in | Fair |
| METAR KORD 130951Z 21007KT 10SM CLR 18/14 A2994 RMK AO2 SLP133 T01830144 $ | |||||||||
| 5:51 AM | 65 °F 64.9 °F 18 °C 18.3 °C | 58 °F 57.9 °F 14 °C 14.4 °C | 78 % | SSW | 7 mph 6 kt 11 km/h | 0 mph 0 kt 0 km/h | 29.95 in | 0.0 in | Partly Cloudy |
| METAR KORD 131051Z 21006KT 10SM SCT150 SCT250 18/14 A2995 RMK AO2 SLP138 T01830144 $ | |||||||||
| 6:51 AM | 67 °F 66.9 °F 19 °C 19.4 °C | 58 °F 57.9 °F 14 °C 14.4 °C | 73 % | SSW | 7 mph 6 kt 11 km/h | 0 mph 0 kt 0 km/h | 29.95 in | 0.0 in | Partly Cloudy |
| METAR KORD 131151Z 21006KT 10SM SCT150 SCT250 19/14 A2995 RMK AO2 SLP138 T01940144 10200 20183 51007 $ | |||||||||
| 7:51 AM | 72 °F 72 °F 22 °C 22.2 °C | 58 °F 57.9 °F 14 °C 14.4 °C | 61 % | SSW | 12 mph 10 kt 19 km/h | 0 mph 0 kt 0 km/h | 29.93 in | 0.0 in | Fair |
| METAR KORD 131251Z 21010KT 10SM FEW150 FEW250 22/14 A2993 RMK AO2 SLP132 T02220144 $ | |||||||||
| 8:51 AM | 75 °F 75 °F 24 °C 23.9 °C | 58 °F 57.9 °F 14 °C 14.4 °C | 55 % | SW | 15 mph 13 kt 24 km/h | 23 mph 20 kt 37 km/h | 29.92 in | 0.0 in | Fair |
| METAR KORD 131351Z 22013G20KT 10SM FEW250 24/14 A2992 RMK AO2 SLP127 T02390144 $ | |||||||||
| 9:51 AM | 78 °F 78.1 °F 26 °C 25.6 °C | 57 °F 57 °F 14 °C 13.9 °C | 48 % | SSW | 17 mph 15 kt 28 km/h | 24 mph 21 kt 39 km/h | 29.90 in | 0.0 in | Fair |
| METAR KORD 131451Z 20015G21KT 10SM FEW250 26/14 A2990 RMK AO2 SLP121 T02560139 57016 $ | |||||||||
| 10:51 AM | 80 °F 80.1 °F 27 °C 26.7 °C | 57 °F 57 °F 14 °C 13.9 °C | 45 % | SW | 18 mph 16 kt 30 km/h | 31 mph 27 kt 50 km/h | 29.90 in | 0.0 in | Partly Cloudy |
| METAR KORD 131551Z 23016G27KT 10SM FEW045 FEW100 SCT250 27/14 A2990 RMK AO2 PK WND 23027/1545 SLP121 T02670139 $ | |||||||||
| 11:51 AM | 81 °F 81 °F 27 °C 27.2 °C | 59 °F 59 °F 15 °C 15 °C | 47 % | SSW | 16 mph 14 kt 26 km/h | 29 mph 25 kt 46 km/h | 29.91 in | 0.0 in | Partly Cloudy |
| METAR KORD 131651Z 21014G25KT 10SM SCT047 SCT100 SCT250 27/15 A2991 RMK AO2 PK WND 20027/1615 SLP124 T02720150 $ | |||||||||
| 12:51 PM | 82 °F 82 °F 28 °C 27.8 °C | 60 °F 60.1 °F 16 °C 15.6 °C | 47 % | SSW | 18 mph 16 kt 30 km/h | 29 mph 25 kt 46 km/h | 29.90 in | 0.0 in | Mostly Cloudy |
| METAR KORD 131751Z 20016G25KT 10SM FEW050 FEW100 BKN250 28/16 A2990 RMK AO2 PK WND 20028/1655 SLP119 T02780156 10278 20194 58002 $ | |||||||||
| 1:51 PM | 83 °F 82.9 °F 28 °C 28.3 °C | 60 °F 60.1 °F 16 °C 15.6 °C | 46 % | SW | 12 mph 10 kt 19 km/h | 28 mph 24 kt 44 km/h | 29.87 in | 0.0 in | Mostly Cloudy |
| METAR KORD 131851Z 22010G24KT 190V260 10SM FEW050 FEW090 BKN250 28/16 A2987 RMK AO2 PK WND 25027/1836 SLP111 CB DSNT SW MOV E T02830156 $ | |||||||||
| 2:51 PM | 82 °F 82 °F 28 °C 27.8 °C | 63 °F 63 °F 17 °C 17.2 °C | 53 % | SSW | 23 mph 20 kt 37 km/h | 31 mph 27 kt 50 km/h | 29.86 in | 0.0 in | Mostly Cloudy |
| METAR KORD 131951Z 20020G27KT 10SM FEW046 FEW075 BKN250 28/17 A2986 RMK AO2 PK WND 22027/1951 SLP106 CB DSNT S T02780172 $ | |||||||||
| 3:51 PM | 81 °F 81 °F 27 °C 27.2 °C | 66 °F 66 °F 19 °C 18.9 °C | 61 % | SSW | 13 mph 11 kt 20 km/h | 22 mph 19 kt 35 km/h | 29.85 in | 0.0 in | Mostly Cloudy |
| METAR KORD 132051Z 21011G19KT 10SM FEW046 SCT065 BKN250 27/19 A2985 RMK AO2 SLP104 T02720189 56014 $ | |||||||||
Time Series
Summary
| Temperature (°F) Temperature (°C) | Actual | |
| High Temp | ||
| Low Temp | ||
| Day Average Temp | ||
| Precipitation (in) | Actual | |
| Precipitation | ||
| Dew Point (°F) Dew Point (°C) | Actual | |
| High | ||
| Low | ||
| Average | ||
| Humidity (%) | Actual | |
| Average Humidity | ||
| Wind (mph) Wind (kt) Wind (km/h) | Actual | |
| Max Wind Speed | ||
| Max Wind Gust | ||
| Visibility | ||
| Pressure (in) | Actual | |
| Average Pressure | ||
| Astronomy | Day Length | Rise / Set |
| Actual Time | 15h 15m | 5:14 AM / 8:29 PM |
| Civil Twilight | 4:41 AM / 9:02 PM | |
| Nautical Twilight | 3:57 AM / 9:46 PM | |
| Astronomical Twilight | 3:04 AM / 10:39 PM | |
| Moon: New Moon | ||
Methodology
Day Boundaries & Time
A "day" is defined as midnight to midnight (00:00:00 through 23:59:59) in the station's local time, using the IANA timezone assigned to each station (e.g. America/Chicago, Europe/London). Daylight Saving Time transitions are respected automatically — when a station's local clocks spring forward or fall back, the UTC boundaries of the day shift accordingly. This means a "day" in the spring DST transition is 23 hours, and in the fall transition it is 25 hours. All observations are stored internally in UTC and converted to local time for display.
Temperature
The FAA reports temperature in degrees Celsius. Values are stored to one decimal place — if a source value has additional precision, it is rounded on storage. Fahrenheit values are computed as °F = °C × 9/5 + 32. All temperatures are displayed as whole numbers (rounded to the nearest integer) in both Celsius and Fahrenheit. High and low temperatures are the maximum and minimum observed values for the day. The day average is the arithmetic mean of all observed temperatures, rounded to the nearest whole number.
Dew Point & Relative Humidity
Dew point is stored and displayed using the same rounding method as temperature (whole numbers). Relative humidity is not reported directly in METARs — it is calculated from the temperature and dew point using the Magnus formula: RH = 100 × exp[(17.27 × Td)/(237.7 + Td) − (17.27 × T)/(237.7 + T)], where T is temperature and Td is dew point, both in °C. The result is rounded to the nearest whole percent and clamped between 0% and 100%.
Wind
Wind direction is reported in degrees true (0–360). The compass direction shown (N, NNE, NE, etc.) divides the compass into 16 sectors of 22.5° each. Variable winds (reported as "VRB" in the METAR) are displayed as "CALM". Wind speed is reported in knots (integer). Miles per hour is computed as mph = kt × 1.15078 and kilometers per hour as km/h = kt × 1.852, both displayed as whole numbers. Wind gust is shown only when the METAR includes a gust value.
Pressure
The altimeter setting is reported in inches of mercury (inHg) to two decimal places. This is the station pressure corrected to sea level and is the value displayed. When the METAR also includes sea level pressure in millibars, that value is used in daily summary calculations.
Precipitation
Precipitation accumulations (1-hour, 3-hour, 6-hour, and 24-hour) are included when reported by the station. A value of 0.0005 inches represents trace precipitation in the FAA convention. The daily total in the summary is the sum of all 1-hour accumulations that exceed trace. Not all stations report precipitation data.
Sky Condition & Weather
The "Condition" column is derived from two METAR fields. If a weather phenomena code is present (e.g. RA for rain, SN for snow, FG for fog, TSRA for thunderstorms), it takes priority and the intensity prefix (- for light, + for heavy) is included. When no active weather is reported, the condition is derived from the highest sky cover layer: CLR/SKC/FEW = Fair, SCT = Partly Cloudy, BKN = Mostly Cloudy, OVC = Overcast.