This report describes the typical weather at the Lyon-Saint Exupéry Airport (Satolas Airport) (Lyon, France) weather station over the course of an average May. It is based on the historical records from 1975 to 2012. Earlier records are either unavailable or unreliable.
Lyon 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 (94%) and forests (4%).
The month of May is characterized by rising daily high temperatures, with daily highs increasing from 65°F to 72°F over the course of the month, exceeding 82°F or dropping below 54°F only one day in ten.
Over the course of May, the length of the day is increasing. From the start to the end of the month, the length of the day increases by 1:07 hours, implying an average day-over-day increase of 2.2 minutes.
The shortest day of the month is May 1 with 14:21 hours of daylight; the longest day is May 31 with 15:28 hours of daylight.
The earliest sunrise is at 5:54am on May 31; the latest sunset is at 9:22pm on May 31; the latest sunrise is at 6:26am on May 1; the earliest sunset is at 8:47pm on May 1.
Daylight savings time is observed in 2012 but it neither starts nor ends in May, so the entire month is in daylight time.
The median cloud cover ranges from 57% (partly cloudy) to 64% (partly cloudy). The trend is for the sky to be clearing with the median cloud cover decreasing by 7% from the start to the end of the month.
On May 16, a representative day, the sky is clear or mostly clear 33% of the time, partly cloudy 22% of the time, and mostly cloudy or overcast 34% of the time.
The average probability that some form of precipitation will be observed in a given day is 51%, with little variation over the course of the month.
Throughout May, the most common forms of precipitation are moderate rain, thunderstorms, and light rain.
Moderate rain is the most severe precipitation observed during 55% of those days with precipitation. It is most likely around May 1, when it is observed during 31% of all days.
Thunderstorms are the most severe precipitation observed during 28% of those days with precipitation. They are most likely around May 31, when it is observed during 18% of all days.
Light rain is the most severe precipitation observed during 14% of those days with precipitation. It is most likely around May 2, when it is observed during 8% of all days.
Either snow is exceptionally unlikely to fall at this location in May or this station does not reliably report precipitation types.
The relative humidity typically ranges from 48% (comfortable) to 91% (very humid) over the course of a typical May, rarely dropping below 30% (comfortable) and reaching as high as 100% (very humid).
The air is driest around May 24, at which time the relative humidity drops below 55% (mildly humid) three days out of four; it is most humid around May 28, rising above 87% (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 May, the dew point typically varies from 40°F (dry) to 56°F (comfortable) and is rarely below 32°F (dry) or above 62°F (mildy humid).
The time of the month between May 5 and May 31 is the most comfortable, with dew points that are neither too dry nor too muggy.
Over the course of May typical wind speeds vary from 1 mph to 14 mph (light air to moderate breeze), rarely exceeding 22 mph (fresh breeze).
The highest average wind speed of 7 mph (light breeze) occurs around May 1, at which time the average daily maximum wind speed is 14 mph (moderate breeze).
The lowest average wind speed of 7 mph (light breeze) occurs around May 31, at which time the average daily maximum wind speed is 13 mph (moderate breeze).