This report describes the typical weather at the Paris Orly Airport (Paris, France) weather station over the course of an average July. It is based on the historical records from 1974 to 2012. Earlier records are either unavailable or unreliable.
Paris has a mild humid temperate climate with warm summers and no dry season. The area within 25 mi of this station is covered by croplands (74%), built-up areas (18%), and forests (6%).
The month of July is characterized by gradually rising daily high temperatures, with daily highs ranging from 74°F to 78°F over the course of the month, exceeding 88°F or dropping below 65°F only one day in ten.
Over the course of July, the length of the day is gradually decreasing. From the start to the end of the month, the length of the day decreases by 58 minutes, implying an average day-over-day decrease of 1.9 minutes.
The shortest day of the month is July 31 with 15:07 hours of daylight; the longest day is July 1 with 16:05 hours of daylight.
The earliest sunrise is at 5:52am on July 1; the latest sunset is at 9:57pm on July 1; the latest sunrise is at 6:23am on July 31; the earliest sunset is at 9:30pm on July 31.
Daylight savings time is observed in 2012 but it neither starts nor ends in July, so the entire month is in daylight time.
The median cloud cover ranges from 49% (partly cloudy) to 54% (partly cloudy). The trend is for the sky to be clearing with the median cloud cover decreasing by 5% from the start to the end of the month.
On July 16, a representative day, the sky is clear or mostly clear 41% of the time, partly cloudy 25% of the time, and mostly cloudy or overcast 29% of the time.
The average probability that some form of precipitation will be observed in a given day is 43%, with little variation over the course of the month.
Throughout July, the most common forms of precipitation are moderate rain and thunderstorms.
Moderate rain is the most severe precipitation observed during 58% of those days with precipitation. It is most likely around July 1, when it is observed during 27% of all days.
Thunderstorms are the most severe precipitation observed during 30% of those days with precipitation. They are most likely around July 25, when it is observed during 13% of all days.
Either snow is exceptionally unlikely to fall at this location in July or this station does not reliably report precipitation types.
The relative humidity typically ranges from 45% (comfortable) to 91% (very humid) over the course of a typical July, rarely dropping below 30% (comfortable) and reaching as high as 100% (very humid).
The air is driest around July 30, at which time the relative humidity drops below 52% (mildly humid) three days out of four; it is most humid around July 3, rising above 86% (very humid) three days out of four.
Dew point is often a better measure of how comfortable a person will find the weather than relative humidity because it more directly relates to whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid.
Over the course of a typical July, the dew point typically varies from 50°F (dry) to 60°F (comfortable) and is rarely below 43°F (dry) or above 66°F (muggy).
The time of the month between July 1 and July 31 is the most comfortable, with dew points that are neither too dry nor too muggy.
Over the course of July typical wind speeds vary from 2 mph to 14 mph (light air to moderate breeze), rarely exceeding 20 mph (fresh breeze).
The highest average wind speed of 9 mph (gentle breeze) occurs around July 1, at which time the average daily maximum wind speed is 14 mph (moderate breeze).
The lowest average wind speed of 8 mph (gentle breeze) occurs around July 31, at which time the average daily maximum wind speed is 13 mph (moderate breeze).