This report describes the typical weather at the Chicago Midway International Airport (Chicago, Illinois, United States) weather station over the course of an average March 22. It is based on the historical records from 1974 to 2012. Earlier records are either unavailable or unreliable.
Chicago, Illinois has a humid continental climate with hot summers and no dry season. The area within 25 mi of this station is covered by built-up areas (36%), oceans and seas (24%), grasslands (23%), croplands (14%), and forests (3%).
The temperature typically varies from 36Â°F to 47Â°F and is rarely below 26Â°F or above 64Â°F.
The coolest hours of the day are from 2am to 8am with the coldest at 6am, at which time the temperature is below 41Â°F three days out of four.
The warmest hours of the day are from noon to 6pm with the hottest at 3pm, at which time the temperature is above 38Â°F three days out of four.
The day has gained half its heat by 10am and lost it again by 9pm.
On March 22 the Sun rises at 6:50am and sets at 7:06pm.
Solar noon is at 12:57pm.
For reference, on the longest day of the year the Sun rises at 5:15am and sets at 8:29pm, while on the shortest day of the year it rises at 7:15am and sets at 4:23pm.
Astronomical twilight begins and ends 94 minutes before sunrise and after sunset at 5:16am and 8:40pm, respectively.
Nautical twilight begins and ends 60 minutes before sunrise and after sunset at 5:50am and 8:06pm, respectively.
Civil twilight begins and ends 28 minutes before sunrise and after sunset at 6:22am and 7:34pm, respectively.
Solar twilight begins and ends 36 minutes after sunrise and before sunset at 7:26am and 6:29pm, respectively.
The median cloud cover is 88% (mostly cloudy) and does not vary substantially over the course of the day.
On average, the sky is clear or mostly clear 24% of the time, partly cloudy 13% of the time, and mostly cloudy or overcast 63% of the time.
There is a 50% chance that precipitation will be observed at some point during the day.
The average measured liquid-equivalent quantity of precipitation is 0.067". Among only those days for which there is at least some measured precipitation, the average is 0.233" and the total rarely exceeds 0.494".
When precipitation does occur it is most often in the form of slight rain (33% of days with precipitation have at worst slight rain), slight snow (29%), thunderstorms (16%), moderate snow (8%), and moderate rain (7%).
Precipitation is most likely around midnight and least likely around 1pm.
Either snow is exceptionally unlikely to fall at this location on March 22 or this station does not reliably report precipitation types.
The relative humidity typically ranges from 58% (mildly humid) to 76% (humid), rarely dropping below 35% (comfortable), or exceeding 94% (very humid).
The air is driest at 3pm, at which time the relative humidity is less than 71% (humid) three days out of four; it is most humid at 5am, exceeding 66% (mildly humid) three days out of four.
The dew point ranges from 29Â°F to 31Â°F with an average of 30Â°F.
For reference, comfortable indoor conditions should have a relative humidity between 30% and 50% with a dew point of less than 65Â°F.
Sustained wind speeds typically vary from 10 mph to 14 mph (gentle breeze to moderate breeze) over the course of the day.
The peak sustained wind speed typically occurs around 2pm and is rarely outside the range 8 mph to 21 mph (gentle breeze to fresh breeze).
The wind is most calm around 4am, rarely exceeding 17 mph (moderate breeze).
The wind is most often out of the north east (16% of the time), south (15% of the time), west (15% of the time), east (11% of the time), north (11% of the time), north west (11% of the time), and south west (11% of the time).