September Weather in Santa Cruz Costa RicaDaily high temperatures are around 89°F, rarely falling below 84°F or exceeding 95°F. Daily low temperatures are around 76°F, rarely falling below 74°F or exceeding 80°F. For reference, on March 28, the hottest day of the year, temperatures in Santa Cruz typically range from 78°F to 96°F, while on October 6, the coldest day of the year, they range from 76°F to 88°F. The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on September. 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. Buriti dos Lopes, Brazil (3,151 miles away); Phnom Penh, Cambodia (10,777 miles); and Surabaya, Indonesia (11,180 miles) are the far-away foreign places with temperatures most similar to Santa Cruz (view comparison). CloudsThe month of September in Santa Cruz experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 87% throughout the month. The highest chance of overcast or mostly cloudy conditions is 88% on September 28. The clearest day of the month is September 13, with clear, mostly clear, or partly cloudy conditions 13% of the time. For reference, on June 4, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 91%, while on January 1, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 73%. PrecipitationA wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Santa Cruz, the chance of a wet day over the course of September is increasing, starting the month at 43% and ending it at 49%. For reference, the year's highest daily chance of a wet day is 51% on September 16, and its lowest chance is 1% on March 15. RainfallTo 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 September in Santa Cruz is rapidly increasing, starting the month at 6.6 inches, when it rarely exceeds 14.5 inches or falls below 1.4 inches, and ending the month at 7.7 inches, when it rarely exceeds 17.3 inches or falls below 1.6 inches. The highest average 31-day accumulation is 7.8 inches on September 25. SunOver the course of September in Santa Cruz, the length of the day is gradually decreasing. From the start to the end of the month, the length of the day decreases by 16 minutes, implying an average daily decrease of 34 seconds, and weekly decrease of 3 minutes, 55 seconds. The shortest day of the month is September 30, with 12 hours, 2 minutes of daylight and the longest day is September 1, with 12 hours, 18 minutes of daylight. The latest sunrise of the month in Santa Cruz is 5:32 AM on September 1 and the earliest sunrise is 1 minute, 55 seconds earlier at 5:31 AM on September 30. The latest sunset is 5:51 PM on September 1 and the earliest sunset is 18 minutes earlier at 5:33 PM on September 30. Daylight saving time is not observed in Santa Cruz during 2024. For reference, on June 20, the longest day of the year, the Sun rises at 5:22 AM and sets 12 hours, 44 minutes later, at 6:05 PM, while on December 21, the shortest day of the year, it rises at 5:54 AM and sets 11 hours, 32 minutes later, at 5:26 PM. 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 September 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. 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.
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. The chance that a given day will be muggy in Santa Cruz is essentially constant during September, remaining around 100% throughout. The highest chance of a muggy day during September is 100% on September 23. For reference, on September 22, the muggiest day of the year, there are muggy conditions 100% of the time, while on February 2, the least muggy day of the year, there are muggy conditions 45% of the time. 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 Santa Cruz is essentially constant during September, remaining within 0.2 miles per hour of 6.2 miles per hour throughout. For reference, on January 30, the windiest day of the year, the daily average wind speed is 12.6 miles per hour, while on September 10, the calmest day of the year, the daily average wind speed is 6.0 miles per hour. The lowest daily average wind speed during September is 6.0 miles per hour on September 10. The wind direction in Santa Cruz during September is predominantly out of the east from September 1 to September 3 and the west from September 3 to September 30. Water TemperatureSanta Cruz 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 Santa Cruz is essentially constant during September, remaining around 83°F throughout. 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 Santa Cruz 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. The average accumulated growing degree days in Santa Cruz are rapidly increasing during September, increasing by 893°F, from 7,906°F to 8,798°F, over the course of the month. 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 in Santa Cruz is essentially constant during September, remaining within 0.1 kWh of 4.2 kWh throughout. TopographyFor the purposes of this report, the geographical coordinates of Santa Cruz are 10.261 deg latitude, -85.585 deg longitude, and 190 ft elevation. The topography within 2 miles of Santa Cruz contains significant variations in elevation, with a maximum elevation change of 771 feet and an average elevation above sea level of 224 feet. Within 10 miles contains significant variations in elevation (3,192 feet). Within 50 miles contains large variations in elevation (6,617 feet). The area within 2 miles of Santa Cruz is covered by grassland (38%), trees (25%), cropland (25%), and shrubs (11%), within 10 miles by trees (42%) and grassland (30%), and within 50 miles by water (50%) and trees (20%). Data SourcesThis report illustrates the typical weather in Santa Cruz, 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, Juan Santamaría International Airport, in our network suitable to be used as a proxy for the historical temperature and dew point records of Santa Cruz. At a distance of 154 kilometers from Santa Cruz, further than our threshold of 150 kilometers, this station is deemed insufficiently nearby to be relied upon as our primary source for temperature and dew point records. Consequently, the station records are blended with interpolated values from NASA's MERRA-2 satellite-era reanalysis , and both are corrected for elevation differences according to the International Standard Atmosphere . The weight assigned to the MERRA-2 value depends on the distance from Santa Cruz to the nearest station, increasing from 0% at 150 kilometers to 100% at 200 kilometers. In this case, the MERRA-2 weight is 7%, making the weight assigned to the weather station 93%. 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. |