Climate and Average Weather Year Round in Rio das Ostras BrazilIn Rio das Ostras, the summers are hot, oppressive, wet, and mostly cloudy and the winters are long, comfortable, muggy, windy, and mostly clear. Over the course of the year, the temperature typically varies from 64°F to 89°F and is rarely below 60°F or above 94°F. Based on the tourism score, the best time of year to visit Rio das Ostras for warm-weather activities is from mid May to late September. Average Temperature in Rio das OstrasThe hot season lasts for 3.2 months, from December 18 to March 25, with an average daily high temperature above 87°F. The hottest month of the year in Rio das Ostras is February, with an average high of 88°F and low of 74°F. The cool season lasts for 5.2 months, from May 8 to October 14, with an average daily high temperature below 82°F. The coldest month of the year in Rio das Ostras is July, with an average low of 64°F and high of 80°F.
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. Cifuentes, Cuba (4,043 miles away) and Jicomé, Dominican Republic (3,514 miles) are the far-away foreign places with temperatures most similar to Rio das Ostras (view comparison). CloudsIn Rio das Ostras, 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 Rio das Ostras begins around April 4 and lasts for 6.4 months, ending around October 16. The clearest month of the year in Rio das Ostras is August, during which on average the sky is clear, mostly clear, or partly cloudy 73% of the time. The cloudier part of the year begins around October 16 and lasts for 5.6 months, ending around April 4. The cloudiest month of the year in Rio das Ostras is January, during which on average the sky is overcast or mostly cloudy 69% of the time.
PrecipitationA wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Rio das Ostras varies significantly throughout the year. The wetter season lasts 5.4 months, from October 21 to April 2, with a greater than 37% chance of a given day being a wet day. The month with the most wet days in Rio das Ostras is December, with an average of 17.6 days with at least 0.04 inches of precipitation. The drier season lasts 6.6 months, from April 2 to October 21. The month with the fewest wet days in Rio das Ostras is July, with an average of 5.1 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 Rio das Ostras is December, with an average of 17.6 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 59% on December 19.
RainfallTo 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. Rio das Ostras experiences extreme seasonal variation in monthly rainfall. Rain falls throughout the year in Rio das Ostras. The month with the most rain in Rio das Ostras is December, with an average rainfall of 7.1 inches. The month with the least rain in Rio das Ostras is July, with an average rainfall of 1.3 inches.
SunThe length of the day in Rio das Ostras varies over the course of the year. In 2024, the shortest day is June 20, with 10 hours, 45 minutes of daylight; the longest day is December 21, with 13 hours, 31 minutes of daylight.
The earliest sunrise is at 4:54 AM on November 28, and the latest sunrise is 1 hour, 34 minutes later at 6:28 AM on July 3. The earliest sunset is at 5:10 PM on June 6, and the latest sunset is 1 hour, 27 minutes later at 6:37 PM on January 14. Daylight saving time (DST) is not observed in Rio das Ostras during 2024. The figure below presents a compact representation of the sun's elevation (the angle of the sun above the horizon) and azimuth (its compass bearing) for every hour of every day in the reporting period. The horizontal axis is the day of the year and the vertical axis is the hour of the day. For a given day and hour of that day, the background color indicates the azimuth of the sun at that moment. The black isolines are contours of constant solar elevation. MoonThe figure below presents a compact representation of key lunar data for 2024. 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. HumidityWe 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. Rio das Ostras experiences extreme seasonal variation in the perceived humidity. The muggier period of the year lasts for 9.6 months, from September 1 to June 21, during which time the comfort level is muggy, oppressive, or miserable at least 57% of the time. The month with the most muggy days in Rio das Ostras is January, with 30.9 days that are muggy or worse. The month with the fewest muggy days in Rio das Ostras is July, with 14.4 days that are muggy or worse.
WindThis 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 Rio das Ostras experiences mild seasonal variation over the course of the year. The windier part of the year lasts for 4.6 months, from July 12 to November 29, with average wind speeds of more than 9.7 miles per hour. The windiest month of the year in Rio das Ostras is September, with an average hourly wind speed of 11.1 miles per hour. The calmer time of year lasts for 7.5 months, from November 29 to July 12. The calmest month of the year in Rio das Ostras is March, with an average hourly wind speed of 8.3 miles per hour.
The predominant average hourly wind direction in Rio das Ostras varies throughout the year. The wind is most often from the east for 2.9 months, from February 27 to May 24 and for 3.9 months, from August 8 to December 5, with a peak percentage of 44% on October 15. The wind is most often from the north for 2.5 months, from May 24 to August 8 and for 2.8 months, from December 5 to February 27, with a peak percentage of 39% on June 22. Water TemperatureRio das Ostras 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 some seasonal variation over the course of the year. The time of year with warmer water lasts for 2.6 months, from February 6 to April 26, with an average temperature above 76°F. The month of the year in Rio das Ostras with the warmest water is March, with an average temperature of 77°F. The time of year with cooler water lasts for 3.4 months, from July 11 to October 24, with an average temperature below 72°F. The month of the year in Rio das Ostras with the coolest water is September, with an average temperature of 70°F.
Best Time of Year to VisitTo characterize how pleasant the weather is in Rio das Ostras 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 Rio das Ostras for general outdoor tourist activities is from mid May to late September, with a peak score in the first week of August. Tourism Score in Rio das OstrasThe beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best times of year to visit Rio das Ostras for hot-weather activities are from mid April to early July and from early August to early October, with a peak score in the last week of April. Beach/Pool Score in Rio das OstrasMethodologyFor 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. Growing SeasonDefinitions 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). Temperatures in Rio das Ostras are sufficiently warm year round that it is not entirely meaningful to discuss the growing season in these terms. We nevertheless include the chart below as an illustration of the distribution of temperatures experienced throughout the year. 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. Solar EnergyThis 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 some seasonal variation over the course of the year. The brighter period of the year lasts for 5.0 months, from October 3 to March 1, with an average daily incident shortwave energy per square meter above 6.0 kWh. The brightest month of the year in Rio das Ostras is November, with an average of 6.4 kWh. The darker period of the year lasts for 2.5 months, from May 10 to July 27, with an average daily incident shortwave energy per square meter below 4.5 kWh. The darkest month of the year in Rio das Ostras is June, with an average of 4.0 kWh.
TopographyFor the purposes of this report, the geographical coordinates of Rio das Ostras are -22.527 deg latitude, -41.945 deg longitude, and 36 ft elevation. The topography within 2 miles of Rio das Ostras contains only modest variations in elevation, with a maximum elevation change of 167 feet and an average elevation above sea level of 23 feet. Within 10 miles contains only modest variations in elevation (2,280 feet). Within 50 miles contains large variations in elevation (7,385 feet). The area within 2 miles of Rio das Ostras is covered by water (53%), shrubs (15%), trees (14%), and grassland (10%), within 10 miles by water (53%) and trees (19%), and within 50 miles by water (55%) and trees (23%). Data SourcesThis report illustrates the typical weather in Rio das Ostras, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016. Temperature and Dew PointThere is only a single weather station, Benedito Lacerda Airport, in our network suitable to be used as a proxy for the historical temperature and dew point records of Rio das Ostras. At a distance of 28 kilometers from Rio das Ostras, closer than our threshold of 150 kilometers, this station is deemed sufficiently nearby to be relied upon as our primary source for temperature and dew point records. The station records are corrected for the elevation difference between the station and Rio das Ostras according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations. Please note that the station records themselves may additionally have been back-filled using other nearby stations or the MERRA-2 reanalysis. Other DataAll 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 © OpenStreetMap contributors. DisclaimerThe 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. Please review our full terms contained on our Terms of Service page. |