KMDW — CHICAGO
Chicago, IL, US · America/Chicago · 41.7860°, -87.7524° · 188m elevation
Daily METAR Observations
| Time | Temperature | Dew Point | Humidity | Wind | Wind Speed | Wind Gust | Pressure | Precip. | Condition |
|---|---|---|---|---|---|---|---|---|---|
| 12:53 AM | 71 °F 71.1 °F 22 °C 21.7 °C | 63 °F 63 °F 17 °C 17.2 °C | 76 % | SSW | 20 mph 17 kt 32 km/h | 27 mph 23 kt 43 km/h | 29.77 in | 0.0 in | Overcast |
| METAR KMDW 140553Z 21017G23KT 10SM FEW047 OVC250 22/17 A2977 RMK AO2 PK WND 21027/0512 SLP072 T02170172 10239 20217 402610172 50002 | |||||||||
| 1:53 AM | 71 °F 71.1 °F 22 °C 21.7 °C | 62 °F 62.1 °F 17 °C 16.7 °C | 73 % | SSW | 21 mph 18 kt 33 km/h | 30 mph 26 kt 48 km/h | 29.75 in | 0.0 in | Overcast |
| METAR KMDW 140653Z 21018G26KT 10SM SCT048 OVC250 22/17 A2975 RMK AO2 PK WND 20028/0610 SLP066 FRQ LTGIC DSNT NW-N CB DSNT NW-N T02170167 | |||||||||
| 2:53 AM | 71 °F 71.1 °F 22 °C 21.7 °C | 62 °F 62.1 °F 17 °C 16.7 °C | 73 % | SW | 21 mph 18 kt 33 km/h | 30 mph 26 kt 48 km/h | 29.74 in | 0.0 in | Overcast |
| METAR KMDW 140753Z 22018G26KT 10SM FEW060 OVC250 22/17 A2974 RMK AO2 PK WND 22028/0701 SLP063 FRQ LTGIC DSNT NW-N CB DSNT NW-N T02170167 | |||||||||
| 3:45 AM | 66 °F 66 °F 19 °C 18.9 °C | 56 °F 55.9 °F 13 °C 13.3 °C | 70 % | N | 21 mph 18 kt 33 km/h | 32 mph 28 kt 52 km/h | 29.81 in | 0.0 in | Overcast |
| SPECI KMDW 140845Z 01018G28KT 10SM BKN025 OVC250 19/13 A2981 RMK AO2 PK WND 36029/0834 WSHFT 0829 FRQ LTGIC DSNT NW-N-NE CB DSNT NW-N-NE T01890133 | |||||||||
| 3:53 AM | 65 °F 64.9 °F 18 °C 18.3 °C | 55 °F 55 °F 13 °C 12.8 °C | 70 % | N | 14 mph 12 kt 22 km/h | 27 mph 23 kt 43 km/h | 29.82 in | 0.0 in | Overcast |
| METAR KMDW 140853Z 36012G23KT 10SM FEW018 BKN025 OVC035 18/13 A2982 RMK AO2 PK WND 36029/0834 WSHFT 0829 SLP090 OCNL LTGIC DSNT NW-N-NE CB DSNT NW-N-NE T01830128 53016 | |||||||||
| 4:13 AM | 64 °F 64 °F 18 °C 17.8 °C | 55 °F 55 °F 13 °C 12.8 °C | 73 % | N | 15 mph 13 kt 24 km/h | 0 mph 0 kt 0 km/h | 29.84 in | 0.0 in | Thunderstorms |
| SPECI KMDW 140913Z 01013KT 10SM TS FEW018 BKN025 OVC039CB 18/13 A2984 RMK AO2 TSB10 FRQ LTGIC N TS N MOV E T01780128 | |||||||||
| 4:31 AM | 63 °F 63 °F 17 °C 17.2 °C | 57 °F 57 °F 14 °C 13.9 °C | 81 % | NE | 10 mph 9 kt 17 km/h | 0 mph 0 kt 0 km/h | 29.82 in | 0.01 in | Light Rain |
| SPECI KMDW 140931Z 05009KT 10SM -RA BKN034 BKN043 BKN100 17/14 A2982 RMK AO2 RAB14 TSB10E30 OCNL LTGIC DSNT NE CB DSNT NE P0000 T01720139 | |||||||||
| 4:53 AM | 62 °F 62.1 °F 17 °C 16.7 °C | 55 °F 55 °F 13 °C 12.8 °C | 78 % | ENE | 10 mph 9 kt 17 km/h | 0 mph 0 kt 0 km/h | 29.82 in | 0.01 in | Overcast |
| METAR KMDW 140953Z 06009KT 10SM FEW037 SCT100 OVC250 17/13 A2982 RMK AO2 SLP089 RAB14E39 TSB10E30 OCNL LTGIC DSNT E CB DSNT E P0000 T01670128 | |||||||||
| 5:53 AM | 60 °F 60.1 °F 16 °C 15.6 °C | 54 °F 54 °F 12 °C 12.2 °C | 80 % | E | 15 mph 13 kt 24 km/h | 0 mph 0 kt 0 km/h | 29.84 in | 0.0 in | Overcast |
| METAR KMDW 141053Z 08013KT 10SM BKN035 BKN047 OVC055 16/12 A2984 RMK AO2 SLP099 FRQ LTGICCG DSNT SW-W CB DSNT SW-W T01560122 | |||||||||
| 6:14 AM | 59 °F 59 °F 15 °C 15 °C | 54 °F 54 °F 12 °C 12.2 °C | 83 % | ENE | 13 mph 11 kt 20 km/h | 0 mph 0 kt 0 km/h | 29.87 in | 0.0 in | Thunderstorms |
| SPECI KMDW 141114Z 06011KT 10SM TS BKN036 OVC047CB 15/12 A2987 RMK AO2 TSB08 PRESRR FRQ LTGICCG S-SW-W TS S-SW-W MOV NE T01500122 | |||||||||
| 6:48 AM | 57 °F 57.2 °F 14 °C 14 °C | 54 °F 53.6 °F 12 °C 12 °C | 88 % | ESE | 7 mph 6 kt 11 km/h | 0 mph 0 kt 0 km/h | 29.86 in | 0.02 in | Light Rain |
| SPECI KMDW 141148Z 12006KT 9SM -RA BKN038 BKN050 OVC110 14/12 A2986 RMK AO2 RAB23 TSB08E42 OCNL LTGICCCCG DSNT SE-S CB DSNT SE-S P0002 | |||||||||
| 6:53 AM | 58 °F 57.9 °F 14 °C 14.4 °C | 55 °F 55 °F 13 °C 12.8 °C | 90 % | ESE | 7 mph 6 kt 11 km/h | 0 mph 0 kt 0 km/h | 29.87 in | 0.02 in | Light Rain |
| METAR KMDW 141153Z 12006KT 10SM -RA SCT038 BKN050 OVC110 14/13 A2987 RMK AO2 RAB23 TSB08E42 SLP108 OCNL LTGICCCCG DSNT SE CB DSNT SE P0002 60002 70003 T01440128 10222 20144 51017 | |||||||||
| 7:53 AM | 58 °F 57.9 °F 14 °C 14.4 °C | 55 °F 55 °F 13 °C 12.8 °C | 90 % | SSE | 15 mph 13 kt 24 km/h | 23 mph 20 kt 37 km/h | 29.84 in | 0.03 in | Mostly Cloudy |
| METAR KMDW 141253Z 15013G20KT 10SM FEW025 BKN055 BKN110 BKN250 14/13 A2984 RMK AO2 RAE14B32E49 SLP099 P0003 T01440128 | |||||||||
| 8:53 AM | 60 °F 60.1 °F 16 °C 15.6 °C | 56 °F 55.9 °F 13 °C 13.3 °C | 86 % | S | 6 mph 5 kt 9 km/h | 0 mph 0 kt 0 km/h | 29.86 in | 0.0 in | Overcast |
| METAR KMDW 141353Z 18005KT 10SM SCT045 OVC060 16/13 A2986 RMK AO2 SLP106 T01560133 | |||||||||
| 9:53 AM | 65 °F 64.9 °F 18 °C 18.3 °C | 60 °F 60.1 °F 16 °C 15.6 °C | 84 % | S | 9 mph 8 kt 15 km/h | 0 mph 0 kt 0 km/h | 29.84 in | 0.0 in | Mostly Cloudy |
| METAR KMDW 141453Z 18008KT 10SM FEW047 FEW065 BKN130 BKN250 18/16 A2984 RMK AO2 SLP097 60003 T01830156 56009 | |||||||||
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 | 13h 21m | 6:10 AM / 7:32 PM |
| Civil Twilight | 5:42 AM / 7:59 PM | |
| Nautical Twilight | 5:08 AM / 8:34 PM | |
| Astronomical Twilight | 4:31 AM / 9:10 PM | |
| Moon: Waning Crescent | ||
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.