Average Weather in Rome Italy
In Rome, the summers are short, hot, humid, dry, and mostly clear and the winters are long, cold, wet, and partly cloudy. Over the course of the year, the temperature typically varies from 37°F to 89°F and is rarely below 28°F or above 95°F.
The hot season lasts for 2.8 months, from June 16 to September 11, with an average daily high temperature above 81°F. The hottest day of the year is August 5, with an average high of 89°F and low of 66°F.
The cool season lasts for 4.0 months, from November 19 to March 18, with an average daily high temperature below 61°F. The coldest day of the year is January 13, with an average low of 37°F and high of 53°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, 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 Rome, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.
The clearer part of the year in Rome begins around June 9 and lasts for 3.1 months, ending around September 12. On July 21, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 88% of the time, and overcast or mostly cloudy 12% of the time.
The cloudier part of the year begins around September 12 and lasts for 8.9 months, ending around June 9. On November 29, the cloudiest day of the year, the sky is overcast or mostly cloudy 48% of the time, and clear, mostly clear, or partly cloudy 52% of the time.
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Rome varies throughout the year.
The wetter season lasts 8.1 months, from September 8 to May 11, with a greater than 20% chance of a given day being a wet day. The chance of a wet day peaks at 34% on November 19.
The drier season lasts 3.9 months, from May 11 to September 8. The smallest chance of a wet day is 7% on August 2.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 34% on November 19.
Daily Chance of Precipitation
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Rome experiences significant seasonal variation in monthly rainfall.
Rain falls throughout the year in Rome. The most rain falls during the 31 days centered around November 18, with an average total accumulation of 3.7 inches.
The least rain falls around July 25, with and average total accumulation of 0.6 inches.
Average Monthly Rainfall
The length of the day in Rome varies significantly over the course of the year. In 2017, the shortest day is December 21, with 9 hours, 8 minutes of daylight; the longest day is June 21, with 15 hours, 14 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:34 AM on June 15, and the latest sunrise is 2 hours, 4 minutes later at 7:37 AM on January 3. The earliest sunset is at 4:38 PM on December 8, and the latest sunset is 4 hours, 11 minutes later at 8:49 PM on June 27.
Daylight saving time (DST) is observed in Rome during 2017, starting in the spring on March 26, lasting 7.1 months, and ending in the fall on October 29.
Sunrise & Sunset with Twilight and Daylight Saving Time
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.
Rome experiences extreme seasonal variation in the perceived humidity.
The muggier period of the year lasts for 3.6 months, from June 15 to October 2, during which time the comfort level is muggy, oppressive, or miserable at least 13% of the time. The muggiest day of the year is August 12, with muggy conditions 51% of the time.
The least muggy day of the year is December 17, when muggy conditions are essentially unheard of.
Humidity Comfort Levels
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 does not vary significantly over the course of the year, remaining within 0.4 miles per hour of 4.1 miles per hour throughout.
Average Wind Speed
The predominant average hourly wind direction in Rome varies throughout the year.
The wind is most often from the south for 2.3 months, from March 4 to May 13 and for 1.7 months, from September 20 to November 11, with a peak percentage of 34% on October 18. The wind is most often from the west for 4.2 months, from May 13 to September 20, with a peak percentage of 46% on July 24. The wind is most often from the east for 3.8 months, from November 11 to March 4, with a peak percentage of 32% on January 1.
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 water temperature experiences significant seasonal variation over the course of the year.
The time of year with warmer water lasts for 2.8 months, from June 29 to September 23, with an average temperature above 73°F. The day of the year with the warmest water is August 12, with an average temperature of 78°F.
The time of year with cooler water lasts for 4.5 months, from December 15 to April 30, with an average temperature below 61°F. The day of the year with the coolest water is February 26, with an average temperature of 57°F.
Average Water Temperature
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 experiences extreme seasonal variation over the course of the year.
The brighter period of the year lasts for 3.3 months, from May 10 to August 18, with an average daily incident shortwave energy per square meter above 6.5 kWh. The brightest day of the year is July 6, with an average of 7.7 kWh.
The darker period of the year lasts for 3.6 months, from October 27 to February 15, with an average daily incident shortwave energy per square meter below 3.0 kWh. The darkest day of the year is December 16, with an average of 1.7 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Rome are 41.892 deg latitude, 12.511 deg longitude, and 141 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: Rome Urbe Airport (67%, 7 kilometers, north); Roma Ciampino Airport (22%, 12 kilometers, southeast); and Leonardo da Vinci–Fiumicino Airport (11%, 24 kilometers, southwest).
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , 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 aiports 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.