Climate and Average Weather Year Round in San Marino San Marino
In San Marino, the summers are warm, humid, and mostly clear and the winters are very cold, windy, and partly cloudy. Over the course of the year, the temperature typically varies from 32°F to 84°F and is rarely below 25°F or above 91°F.
Based on the beach/pool score, the best time of year to visit San Marino for hot-weather activities is from late June to late August.
Climate in San Marino
The warm season lasts for 3.2 months, from June 7 to September 13, with an average daily high temperature above 76°F. The hottest month of the year in San Marino is July, with an average high of 83°F and low of 64°F.
The cool season lasts for 3.5 months, from November 21 to March 7, with an average daily high temperature below 52°F. The coldest month of the year in San Marino is January, with an average low of 33°F and high of 44°F.
Average High and Low Temperature in San Marino
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 San Marino
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
In San Marino, 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 San Marino begins around June 8 and lasts for 3.4 months, ending around September 22.
The clearest month of the year in San Marino is July, during which on average the sky is clear, mostly clear, or partly cloudy 81% of the time.
The cloudier part of the year begins around September 22 and lasts for 8.6 months, ending around June 8.
The cloudiest month of the year in San Marino is December, during which on average the sky is overcast or mostly cloudy 55% of the time.
Cloud Cover Categories in San Marino
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. The chance of wet days in San Marino varies throughout the year.
The wetter season lasts 9.5 months, from August 31 to June 16, with a greater than 22% chance of a given day being a wet day. The month with the most wet days in San Marino is November, with an average of 8.5 days with at least 0.04 inches of precipitation.
The drier season lasts 2.5 months, from June 16 to August 31. The month with the fewest wet days in San Marino is July, with an average of 4.6 days with at least 0.04 inches of precipitation.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. The month with the most days of rain alone in San Marino is November, with an average of 8.4 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 29% on November 16.
Daily Chance of Precipitation in San Marino
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. San Marino experiences some seasonal variation in monthly rainfall.
Rain falls throughout the year in San Marino. The month with the most rain in San Marino is November, with an average rainfall of 2.9 inches.
The month with the least rain in San Marino is July, with an average rainfall of 1.2 inches.
Average Monthly Rainfall in San Marino
As with rainfall, we consider the snowfall accumulated over a sliding 31-day period centered around each day of the year. San Marino experiences some seasonal variation in monthly snowfall.
The snowy period of the year lasts for 3.3 weeks, from December 31 to January 23, with a sliding 31-day snowfall of at least 1.0 inches. The month with the most snow in San Marino is January, with an average snowfall of 1.1 inches.
The snowless period of the year lasts for 11 months, from January 23 to December 31. The least snow falls around July 11, with an average total accumulation of 0.0 inches.
Average Monthly Snowfall in San Marino
The length of the day in San Marino varies significantly over the course of the year. In 2021, the shortest day is December 21, with 8 hours, 54 minutes of daylight; the longest day is June 21, with 15 hours, 29 minutes of daylight.
Hours of Daylight and Twilight in San Marino
The earliest sunrise is at 5:26 AM on June 15, and the latest sunrise is 2 hours, 18 minutes later at 7:44 AM on January 3. The earliest sunset is at 4:32 PM on December 9, and the latest sunset is 4 hours, 25 minutes later at 8:56 PM on June 26.
Daylight saving time (DST) is observed in San Marino during 2021, starting in the spring on March 28, lasting 7.1 months, and ending in the fall on October 31.
Sunrise & Sunset with Twilight and Daylight Saving Time in San Marino
The figure below presents a compact representation of key lunar data for 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.
Moon Rise, Set & Phases in San Marino
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.
San Marino experiences extreme seasonal variation in the perceived humidity.
The muggier period of the year lasts for 3.5 months, from June 6 to September 22, during which time the comfort level is muggy, oppressive, or miserable at least 13% of the time. The month with the most muggy days in San Marino is August, with 13.8 days that are muggy or worse.
The least muggy day of the year is February 26, when muggy conditions are essentially unheard of.
Humidity Comfort Levels in San Marino
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 San Marino experiences significant seasonal variation over the course of the year.
The windier part of the year lasts for 6.3 months, from October 14 to April 23, with average wind speeds of more than 8.4 miles per hour. The windiest month of the year in San Marino is February, with an average hourly wind speed of 9.7 miles per hour.
The calmer time of year lasts for 5.7 months, from April 23 to October 14. The calmest month of the year in San Marino is August, with an average hourly wind speed of 7.0 miles per hour.
Average Wind Speed in San Marino
The predominant average hourly wind direction in San Marino varies throughout the year.
The wind is most often from the east for 1.2 months, from February 18 to March 23; for 3.1 weeks, from April 10 to May 2; and for 5.0 months, from June 26 to November 25, with a peak percentage of 35% on August 26. The wind is most often from the west for 2.6 weeks, from March 23 to April 10; for 1.8 months, from May 2 to June 26; and for 2.6 months, from December 1 to February 18, with a peak percentage of 34% on June 11. The wind is most often from the north for 6.0 days, from November 25 to December 1, with a peak percentage of 27% on November 30.
Wind Direction in San Marino
San Marino 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 3.0 months, from June 20 to September 18, with an average temperature above 73°F. The month of the year in San Marino with the warmest water is August, with an average temperature of 78°F.
The time of year with cooler water lasts for 3.9 months, from December 18 to April 15, with an average temperature below 56°F. The month of the year in San Marino with the coolest water is February, with an average temperature of 51°F.
Average Water Temperature in San Marino
To characterize how pleasant the weather is in San Marino throughout the year, we compute two travel scores.
The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit San Marino for general outdoor tourist activities is from mid May to early October, with a peak score in the second week of September.
Tourism Score in San Marino
The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit San Marino for hot-weather activities is from late June to late August, with a peak score in the third week of July.
Beach/Pool Score in San Marino
For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.
Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.
Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.
Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.
Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.
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 San Marino typically lasts for 8.3 months (255 days), from around March 16 to around November 26, rarely starting before February 19 or after April 5, and rarely ending before November 7 or after December 19.
Time Spent in Various Temperature Bands and the Growing Season in San Marino
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.
Based on growing degree days alone, the first spring blooms in San Marino should appear around April 5, only rarely appearing before March 22 or after April 17.
Growing Degree Days in San Marino
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 3.2 months, from May 11 to August 18, with an average daily incident shortwave energy per square meter above 6.2 kWh. The brightest month of the year in San Marino is July, with an average of 7.2 kWh.
The darker period of the year lasts for 3.5 months, from October 29 to February 14, with an average daily incident shortwave energy per square meter below 2.6 kWh. The darkest month of the year in San Marino is December, with an average of 1.4 kWh.
Average Daily Incident Shortwave Solar Energy in San Marino
For the purposes of this report, the geographical coordinates of San Marino are 43.937 deg latitude, 12.446 deg longitude, and 0 ft elevation.
The topography within 2 miles of San Marino is essentially flat, with a maximum elevation change of 0 feet and an average elevation above sea level of 0 feet. Within 10 miles is also essentially flat (0 feet). Within 50 miles is also essentially flat (0 feet).
The area within 2 miles of San Marino is covered by cropland (52%), trees (37%), and artificial surfaces (11%), within 10 miles by cropland (69%) and trees (22%), and within 50 miles by cropland (37%) and water (30%).
This report illustrates the typical weather in San Marino, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
The details of the data sources used for this report can be found on the Serravalle page.
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.