Average Weather in September in Germiston South Africa
Daily high temperatures increase by 4°F, from 71°F to 76°F, rarely falling below 61°F or exceeding 84°F.
Daily low temperatures increase by 6°F, from 46°F to 52°F, rarely falling below 38°F or exceeding 59°F.
For reference, on January 1, the hottest day of the year, temperatures in Germiston typically range from 60°F to 79°F, while on July 5, the coldest day of the year, they range from 38°F to 62°F.
Average High and Low Temperature in September
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.
Average Hourly Temperature in September
The month of September in Germiston experiences gradually increasing cloud cover, with the percentage of time that the sky is overcast or mostly cloudy increasing from 12% to 18%.
The clearest day of the month is September 1, with clear, mostly clear, or partly cloudy conditions 88% of the time.
For reference, on November 25, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 38%, while on July 21, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 92%.
Cloud Cover Categories in September
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. In Germiston, the chance of a wet day over the course of September is very rapidly increasing, starting the month at 5% and ending it at 15%.
For reference, the year's highest daily chance of a wet day is 54% on December 17, and its lowest chance is 1% on July 8.
Probability of Precipitation in September
The average sliding 31-day rainfall during September in Germiston is increasing, starting the month at 0.4 inches, when it rarely exceeds 1.4 inches or falls below -0.0 inches, and ending the month at 1.3 inches, when it rarely exceeds 2.9 inches or falls below 0.2 inches.
Average Monthly Rainfall in September
Over the course of September in Germiston, the length of the day is increasing. From the start to the end of the month, the length of the day increases by 44 minutes, implying an average daily increase of 1 minute, 31 seconds, and weekly increase of 10 minutes, 35 seconds.
The shortest day of the month is September 1, with 11 hours, 35 minutes of daylight and the longest day is September 30, with 12 hours, 19 minutes of daylight.
Hours of Daylight and Twilight in September
The latest sunrise of the month in Germiston is 6:19 AM on September 1 and the earliest sunrise is 32 minutes earlier at 5:47 AM on September 30.
The earliest sunset is 5:54 PM on September 1 and the latest sunset is 12 minutes later at 6:06 PM on September 30.
Daylight saving time is not observed in Germiston during 2021.
For reference, on December 21, the longest day of the year, the Sun rises at 5:11 AM and sets 13 hours, 47 minutes later, at 6:59 PM, while on June 21, the shortest day of the year, it rises at 6:54 AM and sets 10 hours, 30 minutes later, at 5:23 PM.
Sunrise & Sunset with Twilight in September
The figure below presents a compact representation of key lunar data for September 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. 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.
Moon Rise, Set & Phases in September
The chance that a given day will be muggy in Germiston is essentially constant during September, remaining around 0% throughout.
For reference, on January 30, the muggiest day of the year, there are muggy conditions 1% of the time, while on April 11, the least muggy day of the year, there are muggy conditions 0% of the time.
Humidity Comfort Levels in September
dry 55°F comfortable 60°F humid 65°F muggy 70°F oppressive 75°F miserable
The average hourly wind speed in Germiston is essentially constant during September, remaining within 0.2 miles per hour of 9.6 miles per hour throughout.
For reference, on September 25, the windiest day of the year, the daily average wind speed is 9.8 miles per hour, while on March 31, the calmest day of the year, the daily average wind speed is 6.4 miles per hour.
The highest daily average wind speed during September is 9.8 miles per hour on September 25.
Average Wind Speed in September
The hourly average wind direction in Germiston throughout September is predominantly from the north, with a peak proportion of 49% on September 29.
Wind Direction in September
The growing season in Germiston typically lasts for 10 months (318 days), from around July 31 to around June 13, rarely starting after September 6, or ending before May 21.
The month of September in Germiston is more likely than not fully outside of the growing season, with the chance that a given day is in the growing season increasing from 85% to 100% over the course of the month.
Time Spent in Various Temperature Bands and the Growing Season in September
The average accumulated growing degree days in Germiston are increasing during September, increasing by 354°F, from 349°F to 702°F, over the course of the month.
Growing Degree Days in September
The average daily incident shortwave solar energy in Germiston is gradually increasing during September, rising by 0.9 kWh, from 5.9 kWh to 6.7 kWh, over the course of the month.
Average Daily Incident Shortwave Solar Energy in September
For the purposes of this report, the geographical coordinates of Germiston are -26.235 deg latitude, 28.177 deg longitude, and 5,410 ft elevation.
The topography within 2 miles of Germiston contains only modest variations in elevation, with a maximum elevation change of 387 feet and an average elevation above sea level of 5,369 feet. Within 10 miles contains only modest variations in elevation (1,017 feet). Within 50 miles contains very significant variations in elevation (2,730 feet).
The area within 2 miles of Germiston is covered by artificial surfaces (73%) and grassland (23%), within 10 miles by artificial surfaces (64%) and grassland (26%), and within 50 miles by grassland (45%) and cropland (30%).
This report illustrates the typical weather in Germiston, 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 4 weather stations near enough to contribute to our estimation of the temperature and dew point in Germiston.
For each station, the records are corrected for the elevation difference between that station and Germiston 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 Germiston is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Germiston and a given station.
The stations contributing to this reconstruction are: O.R. Tambo International Airport (46%, 13 kilometers, northeast); Rand Airport (25%, 20 kilometers, northwest); Springs (22%, 22 kilometers, east); and Vereeniging (7%, 43 kilometers, southwest).
Time zones for airports and weather stations are provided by AskGeo.com .