Climate and Average Weather Year Round in Bethlehem South AfricaIn Bethlehem, the summers are long and warm; the winters are short, cold, and dry; and it is mostly clear year round. Over the course of the year, the temperature typically varies from 30°F to 79°F and is rarely below 24°F or above 86°F. Based on the tourism score, the best time of year to visit Bethlehem for warm-weather activities is from early December to early April. Average Temperature in BethlehemThe warm season lasts for 4.1 months, from November 9 to March 13, with an average daily high temperature above 75°F. The hottest month of the year in Bethlehem is January, with an average high of 78°F and low of 57°F. The cold season lasts for 2.4 months, from May 26 to August 5, with an average daily high temperature below 64°F. The coldest month of the year in Bethlehem is July, with an average low of 31°F and high of 61°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. Mutquín, Argentina (5,571 miles away); Achiras, Argentina (5,361 miles); and Oakdale, Australia (6,717 miles) are the far-away foreign places with temperatures most similar to Bethlehem (view comparison). CloudsIn Bethlehem, 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 Bethlehem begins around February 14 and lasts for 7.4 months, ending around September 27. The clearest month of the year in Bethlehem is July, during which on average the sky is clear, mostly clear, or partly cloudy 88% of the time. The cloudier part of the year begins around September 27 and lasts for 4.5 months, ending around February 14. The cloudiest month of the year in Bethlehem is November, during which on average the sky is overcast or mostly cloudy 35% 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 Bethlehem varies significantly throughout the year. The wetter season lasts 5.6 months, from October 10 to March 29, with a greater than 24% chance of a given day being a wet day. The month with the most wet days in Bethlehem is January, with an average of 13.8 days with at least 0.04 inches of precipitation. The drier season lasts 6.4 months, from March 29 to October 10. The month with the fewest wet days in Bethlehem is July, with an average of 0.8 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 Bethlehem is January, with an average of 13.8 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 45% on January 22.
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. Bethlehem experiences significant seasonal variation in monthly rainfall. The rainy period of the year lasts for 9.0 months, from August 10 to May 8, with a sliding 31-day rainfall of at least 0.5 inches. The month with the most rain in Bethlehem is January, with an average rainfall of 3.0 inches. The rainless period of the year lasts for 3.0 months, from May 8 to August 10. The month with the least rain in Bethlehem is July, with an average rainfall of 0.3 inches.
SunThe length of the day in Bethlehem varies over the course of the year. In 2024, the shortest day is June 20, with 10 hours, 21 minutes of daylight; the longest day is December 21, with 13 hours, 56 minutes of daylight.
The earliest sunrise is at 5:01 AM on December 1, and the latest sunrise is 1 hour, 57 minutes later at 6:59 AM on July 1. The earliest sunset is at 5:17 PM on June 8, and the latest sunset is 1 hour, 51 minutes later at 7:08 PM on January 11. Daylight saving time (DST) is not observed in Bethlehem 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. The perceived humidity level in Bethlehem, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, remaining a virtually constant 0% throughout.
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 Bethlehem experiences mild seasonal variation over the course of the year. The windier part of the year lasts for 4.4 months, from August 2 to December 15, with average wind speeds of more than 8.2 miles per hour. The windiest month of the year in Bethlehem is September, with an average hourly wind speed of 9.5 miles per hour. The calmer time of year lasts for 7.6 months, from December 15 to August 2. The calmest month of the year in Bethlehem is March, with an average hourly wind speed of 6.9 miles per hour.
The predominant average hourly wind direction in Bethlehem varies throughout the year. The wind is most often from the east for 2.7 months, from January 7 to March 29, with a peak percentage of 45% on February 19. The wind is most often from the west for 9.3 months, from March 29 to January 7, with a peak percentage of 37% on January 1. Best Time of Year to VisitTo characterize how pleasant the weather is in Bethlehem 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 Bethlehem for general outdoor tourist activities is from early December to early April, with a peak score in the last week of February. Tourism Score in BethlehemThe 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 Bethlehem for hot-weather activities is from mid December to late February, with a peak score in the third week of January. Beach/Pool Score in BethlehemMethodologyFor 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). The growing season in Bethlehem typically lasts for 8.4 months (253 days), from around September 3 to around May 14, rarely starting before August 12 or after September 29, and rarely ending before April 20 or after June 5. 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 Bethlehem should appear around August 1, only rarely appearing before July 26 or after August 7. 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 significant seasonal variation over the course of the year. The brighter period of the year lasts for 3.6 months, from October 28 to February 18, with an average daily incident shortwave energy per square meter above 7.2 kWh. The brightest month of the year in Bethlehem is December, with an average of 7.9 kWh. The darker period of the year lasts for 3.0 months, from May 3 to August 4, with an average daily incident shortwave energy per square meter below 4.8 kWh. The darkest month of the year in Bethlehem is June, with an average of 4.0 kWh.
TopographyFor the purposes of this report, the geographical coordinates of Bethlehem are -28.231 deg latitude, 28.307 deg longitude, and 5,348 ft elevation. The topography within 2 miles of Bethlehem contains only modest variations in elevation, with a maximum elevation change of 440 feet and an average elevation above sea level of 5,462 feet. Within 10 miles contains only modest variations in elevation (1,375 feet). Within 50 miles contains very significant variations in elevation (6,545 feet). The area within 2 miles of Bethlehem is covered by artificial surfaces (52%) and cropland (46%), within 10 miles by cropland (75%) and grassland (21%), and within 50 miles by grassland (50%) and cropland (44%). Data SourcesThis report illustrates the typical weather in Bethlehem, 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 are 2 weather stations near enough to contribute to our estimation of the temperature and dew point in Bethlehem. For each station, the records are corrected for the elevation difference between that station and Bethlehem 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 Bethlehem is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Bethlehem 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 Bethlehem 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. 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. |