This report describes the typical weather at the Rome Urbe Airport (Rome, Italy) weather station over the course of an average May. It is based on the historical records from 1998 to 2012. Earlier records are either unavailable or unreliable.
Rome has a mediterranean climate with dry hot summers and mild winters. The area within 25 mi of this station is covered by shrublands (47%), croplands (22%), forests (18%), and oceans and seas (10%).
The month of May is characterized by rising daily high temperatures, with daily highs increasing from 72°F to 79°F over the course of the month, exceeding 86°F or dropping below 66°F only one day in ten.
Over the course of May, the length of the day is gradually increasing. From the start to the end of the month, the length of the day increases by 58 minutes, implying an average day-over-day increase of 1.9 minutes.
The shortest day of the month is May 1 with 14:03 hours of daylight; the longest day is May 31 with 15:01 hours of daylight.
The earliest sunrise is at 5:38am on May 30; the latest sunset is at 8:38pm on May 31; the latest sunrise is at 6:06am on May 1; the earliest sunset is at 8:09pm 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 ranges from 47% (partly cloudy) to 54% (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 13% of the time, partly cloudy 17% of the time, and mostly cloudy or overcast 12% of the time.
The probability that precipitation will be observed at this location varies throughout the month. Precipitation is most likely around May 7, occurring in 31% of days. Precipitation is least likely around May 31, occurring in 23% of days.
Throughout May, the most common forms of precipitation are thunderstorms, light rain, and moderate rain.
Thunderstorms are the most severe precipitation observed during 43% of those days with precipitation. They are most likely around May 10, when it is observed during 13% of all days.
Light rain is the most severe precipitation observed during 29% of those days with precipitation. It is most likely around May 1, when it is observed during 10% of all days.
Moderate rain is the most severe precipitation observed during 23% of those days with precipitation. It is most likely around May 4, 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 45% (comfortable) to 93% (very humid) over the course of a typical May, rarely dropping below 32% (comfortable) and reaching as high as 100% (very humid).
The air is driest around May 31, at which time the relative humidity drops below 51% (mildly humid) three days out of four; it is most humid around May 1, rising above 90% (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 47°F (dry) to 62°F (comfortable) and is rarely below 40°F (dry) or above 67°F (muggy).
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 0 mph to 11 mph (calm to gentle breeze), rarely exceeding 16 mph (moderate breeze).
The highest average wind speed of 4 mph (light breeze) occurs around May 30, at which time the average daily maximum wind speed is 11 mph (gentle breeze).
The lowest average wind speed of 4 mph (light breeze) occurs around May 3, at which time the average daily maximum wind speed is 10 mph (gentle breeze).