This report describes the typical weather at the Lyon Bron Airport (Lyon, France) weather station over the course of an average April. It is based on the historical records from 1974 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 (96%) and forests (2%).
The month of April is characterized by rising daily high temperatures, with daily highs increasing from 58°F to 64°F over the course of the month, exceeding 75°F or dropping below 47°F only one day in ten.
Over the course of April, the length of the day is increasing. From the start to the end of the month, the length of the day increases by 1:29 hours, implying an average day-over-day increase of 3.0 minutes.
The shortest day of the month is April 1 with 12:49 hours of daylight; the longest day is April 30 with 14:18 hours of daylight.
The earliest sunrise is at 6:28am on April 30; the latest sunset is at 8:46pm on April 30; the latest sunrise is at 7:20am on April 1; the earliest sunset is at 8:09pm on April 1.
Daylight saving time is observed in 2012 but it neither starts nor ends in April, so the entire month is in daylight time.
The median cloud cover is 70% (partly cloudy) and does not vary substantially over the course of the month.
On April 15, a representative day, the sky is clear or mostly clear 17% of the time, partly cloudy 14% of the time, and mostly cloudy or overcast 25% of the time.
The average probability that some form of precipitation will be observed in a given day is 42%, with little variation over the course of the month.
Throughout April, the most common forms of precipitation are moderate rain, light rain, and thunderstorms.
Moderate rain is the most severe precipitation observed during 59% of those days with precipitation. It is most likely around April 18, when it is observed during 25% of all days.
Light rain is the most severe precipitation observed during 23% of those days with precipitation. It is most likely around April 1, when it is observed during 10% of all days.
Thunderstorms are the most severe precipitation observed during 12% of those days with precipitation. They are most likely around April 30, when it is observed during 7% of all days.
The likelihood of snow falling is highest around April 1, occurring in 3% of days.
Either snow rarely accumulates at this location in April or snow depth measurements are unavailable or unreliable.
The relative humidity typically ranges from 47% (comfortable) to 96% (very humid) over the course of a typical April, rarely dropping below 29% (dry) and reaching as high as 100% (very humid).
The air is driest around April 19, at which time the relative humidity drops below 55% (mildly humid) three days out of four; it is most humid around April 1, rising above 93% (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 April, the dew point typically varies from 35°F (dry) to 48°F (dry) and is rarely below 26°F (dry) or above 54°F (very comfortable).
Over the course of April typical wind speeds vary from 1 mph to 15 mph (light air to moderate breeze), rarely exceeding 24 mph (strong breeze).
The highest average wind speed of 9 mph (gentle breeze) occurs around April 6, at which time the average daily maximum wind speed is 15 mph (moderate breeze).
The lowest average wind speed of 8 mph (light breeze) occurs around April 29, at which time the average daily maximum wind speed is 14 mph (moderate breeze).