May Weather in Rome Italy
Daily high temperatures increase by 8°F, from 69°F to 77°F, rarely falling below 62°F or exceeding 85°F.
Daily low temperatures increase by 7°F, from 50°F to 56°F, rarely falling below 44°F or exceeding 62°F.
For reference, on August 5, the hottest day of the year, temperatures in Rome typically range from 66°F to 89°F, while on January 13, the coldest day of the year, they range from 37°F to 53°F.
Average High and Low Temperature in May in Rome
The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on May. The horizontal axis is the day, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature in May in Rome
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
The month of May in Rome experiences decreasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy decreasing from 43% to 34%.
The clearest day of the month is May 31, with clear, mostly clear, or partly cloudy conditions 66% of the time.
For reference, on November 29, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 48%, while on July 21, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 88%.
Cloud Cover Categories in May in Rome
0% clear 20% mostly clear 40% partly cloudy 60% mostly cloudy 80% overcast 100%
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Rome, the chance of a wet day over the course of May is rapidly decreasing, starting the month at 23% and ending it at 16%.
For reference, the year's highest daily chance of a wet day is 34% on November 19, and its lowest chance is 7% on August 6.
Probability of Precipitation in May in Rome
To show variation within the month and not just the monthly total, we show the rainfall accumulated over a sliding 31-day period centered around each day.
The average sliding 31-day rainfall during May in Rome is decreasing, starting the month at 1.8 inches, when it rarely exceeds 3.3 inches or falls below 0.5 inches, and ending the month at 1.3 inches, when it rarely exceeds 2.8 inches or falls below 0.2 inches.
Average Monthly Rainfall in May in Rome
Over the course of May in Rome, the length of the day is increasing. From the start to the end of the month, the length of the day increases by 58 minutes, implying an average daily increase of 1 minute, 56 seconds, and weekly increase of 13 minutes, 29 seconds.
The shortest day of the month is May 1, with 14 hours, 3 minutes of daylight and the longest day is May 31, with 15 hours, 0 minutes of daylight.
Hours of Daylight and Twilight in May in Rome
The latest sunrise of the month in Rome is 6:06 AM on May 1 and the earliest sunrise is 28 minutes earlier at 5:37 AM on May 31.
The earliest sunset is 8:08 PM on May 1 and the latest sunset is 29 minutes later at 8:38 PM on May 31.
Daylight saving time is observed in Rome during 2021, but it neither starts nor ends during May, so the entire month is in daylight saving time.
For reference, on June 21, the longest day of the year, the Sun rises at 5:34 AM and sets 15 hours, 14 minutes later, at 8:48 PM, while on December 21, the shortest day of the year, it rises at 7:34 AM and sets 9 hours, 8 minutes later, at 4:41 PM.
Sunrise & Sunset with Twilight in May in Rome
The figure below presents a compact representation of key lunar data for May 2021. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases. The label associated with each bar indicates the date and time that the phase is obtained, and the companion time labels indicate the rise and set times of the Moon for the nearest time interval in which the moon is above the horizon.
Moon Rise, Set & Phases in May in Rome
We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.
The chance that a given day will be muggy in Rome is gradually increasing during May, rising from 0% to 5% over the course of the month.
For reference, on August 10, the muggiest day of the year, there are muggy conditions 51% of the time, while on December 2, the least muggy day of the year, there are muggy conditions 0% of the time.
Humidity Comfort Levels in May in Rome
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.
The average hourly wind speed in Rome is gradually decreasing during May, decreasing from 7.7 miles per hour to 7.1 miles per hour over the course of the month.
For reference, on April 3, the windiest day of the year, the daily average wind speed is 8.5 miles per hour, while on August 12, the calmest day of the year, the daily average wind speed is 6.8 miles per hour.
Average Wind Speed in May in Rome
The wind direction in Rome during May is predominantly out of the south from May 1 to May 13 and the west from May 13 to May 31.
Wind Direction in May in Rome
Rome is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average surface water temperature in Rome is increasing during May, rising by 6°F, from 62°F to 68°F, over the course of the month.
Average Water Temperature in May in Rome
Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).
The growing season in Rome typically lasts for 9.2 months (281 days), from around March 2 to around December 8, rarely starting before February 5 or after March 25, and rarely ending before November 13 or after January 1.
The month of May in Rome is reliably fully within the growing season.
Time Spent in Various Temperature Bands and the Growing Season in May in Rome
frigid 15°F freezing 32°F very cold 45°F cold 55°F cool 65°F comfortable 75°F warm 85°F hot 95°F sweltering
Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.
The average accumulated growing degree days in Rome are increasing during May, increasing by 416°F, from 434°F to 850°F, over the course of the month.
Growing Degree Days in May in Rome
This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.
The average daily incident shortwave solar energy in Rome is gradually increasing during May, rising by 1.0 kWh, from 6.2 kWh to 7.2 kWh, over the course of the month.
Average Daily Incident Shortwave Solar Energy in May in Rome
For the purposes of this report, the geographical coordinates of Rome are 41.892 deg latitude, 12.511 deg longitude, and 171 ft elevation.
The topography within 2 miles of Rome contains only modest variations in elevation, with a maximum elevation change of 249 feet and an average elevation above sea level of 152 feet. Within 10 miles contains only modest variations in elevation (938 feet). Within 50 miles contains very significant variations in elevation (8,110 feet).
The area within 2 miles of Rome is covered by artificial surfaces (97%), within 10 miles by cropland (54%) and artificial surfaces (43%), and within 50 miles by cropland (36%) and water (33%).
This report illustrates the typical weather in Rome, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
There are 3 weather stations near enough to contribute to our estimation of the temperature and dew point in Rome.
For each station, the records are corrected for the elevation difference between that station and Rome according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
The estimated value at Rome is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Rome and a given station.
The stations contributing to this reconstruction are:
To get a sense of how much these sources agree with each other, you can view a comparison of Rome and the stations that contribute to our estimates of its temperature history and climate. Please note that each source's contribution is adjusted for elevation and the relative change present in the MERRA-2 data.
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Algorithms 2nd Edition , by Jean Meeus.
All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.
Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.
Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.
Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .
Time zones for airports and weather stations are provided by AskGeo.com .
Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.
The information on this site is provided as is, without any assurances as to its accuracy or suitability for any purpose. Weather data is prone to errors, outages, and other defects. We assume no responsibility for any decisions made on the basis of the content presented on this site.
We draw particular cautious attention to our reliance on the MERRA-2 model-based reconstructions for a number of important data series. While having the tremendous advantages of temporal and spatial completeness, these reconstructions: (1) are based on computer models that may have model-based errors, (2) are coarsely sampled on a 50 km grid and are therefore unable to reconstruct the local variations of many microclimates, and (3) have particular difficulty with the weather in some coastal areas, especially small islands.
We further caution that our travel scores are only as good as the data that underpin them, that weather conditions at any given location and time are unpredictable and variable, and that the definition of the scores reflects a particular set of preferences that may not agree with those of any particular reader.
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