This report describes the typical weather at the Porto Santo Airport (Porto Santo Island, Portugal) weather station over the course of an average May. It is based on the historical records from 1990 to 2012. Earlier records are either unavailable or unreliable.
Porto Santo Island has a mediterranean climate with dry hot summers and mild winters. The area within 25 mi of this station is covered by oceans and seas (100%).
The month of May is characterized by gradually rising daily high temperatures, with daily highs around 69°F throughout the month, exceeding 73°F or dropping below 65°F only one day in ten.
Over the course of May, the length of the day is gradually increasing. The shortest day of the month is May 1 with 13:31 hours of daylight; the longest day is May 31 with 14:12 hours of daylight.
The earliest sunrise is at 6:58am on May 31; the latest sunset is at 9:09pm on May 31; the latest sunrise is at 7:17am on May 1; the earliest sunset is at 8:48pm on May 1.
Daylight saving 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 is 49% (partly cloudy) and does not vary substantially over the course of the month.
On May 16, a representative day, the sky is clear or mostly clear 38% of the time, partly cloudy 37% of the time, and mostly cloudy or overcast 24% of the time.
The average probability that some form of precipitation will be observed in a given day is 23%, with little variation over the course of the month.
Throughout May, the most common forms of precipitation are moderate rain, drizzle, and light rain.
Moderate rain is the most severe precipitation observed during 50% of those days with precipitation. It is most likely around May 1, when it is observed during 13% of all days.
Drizzle is the most severe precipitation observed during 27% of those days with precipitation. It is most likely around May 26, when it is observed during 7% of all days.
Light rain is the most severe precipitation observed during 17% of those days with precipitation. It is most likely around May 1, when it is observed during 5% 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 60% (mildly humid) to 91% (very humid) over the course of a typical May, rarely dropping below 50% (comfortable) and reaching as high as 100% (very humid).
The air is driest around May 1, at which time the relative humidity drops below 65% (mildly humid) three days out of four; it is most humid around May 19, rising above 84% (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 50°F (very comfortable) to 60°F (comfortable) and is rarely below 45°F (dry) or above 65°F (mildy humid).
The time of the month between May 1 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 5 mph to 16 mph (light breeze to moderate breeze), rarely exceeding 21 mph (fresh breeze).
The highest average wind speed of 11 mph (gentle breeze) occurs around May 1, at which time the average daily maximum wind speed is 16 mph (moderate breeze).
The lowest average wind speed of 10 mph (gentle breeze) occurs around May 17, at which time the average daily maximum wind speed is 15 mph (moderate breeze).