Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
September introduces a marginal temperature uplift, with average high-temperatures adjusting from August's refreshing 15.4°C (59.7°F) to an enjoyable 19.3°C (66.7°F). During September, Williston witnesses a consistent average low-temperature of 7.4°C (45.3°F).Humidity
The average relative humidity in September is 40%.Rainfall
In Williston, during September, the rain falls for 3.1 days and regularly aggregates up to 5mm (0.2") of precipitation. Throughout the year, there are 48.1 rainfall days, and 112mm (4.41") of precipitation is accumulated.Snowfall
Months with snowfall in Williston are July through September. September is the last month it regularly snows. During 0.2 snowfall days, in September, Williston aggregates 1mm (0.04") of snow. In Williston, during the entire year, snow falls for 2 days and aggregates up to 10mm (0.39") of snow.Daylight
The average length of the day in September in Williston is 11h and 55min.On the first day of the month, sunrise is at 06:51 and sunset at 18:20. On the last day of September, sunrise is at 06:14 and sunset at 18:37 SAST.
Sunshine
In Williston, the average sunshine in September is 9.5h.UV index
In September, the average daily maximum UV index is 4. A UV Index value of 3 to 5 symbolizes a moderate threat to health from unsafe exposure to UV radiation for the ordinary person.Note: In September, the maximum UV index of 4 translates into these guidelines:
Take care. Persons with lighter skin might suffer burns in less than 30 minutes. To avoid the Sun's strongest rays, limit exposure around the mid-day period. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes. Warning! The reflection from snow can nearly magnify the Sun's UV radiation twofold.
Frequently asked questions
What are September temperatures in Williston?
What is the average humidity in September in Williston?
How much does it rain in Williston in September?
What is the last month it snows in Williston?
What is the average length of the day in September in Williston?
When is the sunrise / sunset in September in Williston?
How long on average sun shines in September in Williston?
How high is the UV index in September in Williston?
Average temperature in September
Williston, South Africa
- Average high temperature in September: 19.3°C
The warmest month (with the highest average high temperature) is January (29.1°C).
The month with the lowest average high temperature is June (13.2°C).
- Average low temperature in September: 7.4°C
The months with the highest average low temperature are January and February (16.8°C).
The coldest month (with the lowest average low temperature) is July (3.9°C).
Average pressure in September
Williston, South Africa
- Average pressure in September: 1018.5mbar
The month with the highest atmospheric pressure is July (1023.4mbar).
The month with the lowest atmospheric pressure is January (1011.7mbar).
Average wind speed in September
Williston, South Africa
- Average wind speed in September: 17.7km/h
The windiest month (with the highest average wind speed) is June (19.2km/h).
The calmest month (with the lowest average wind speed) is March (15.8km/h).
Average humidity in September
Williston, South Africa
- Average humidity in September: 40%
The month with the highest relative humidity is June (57%).
The month with the lowest relative humidity is November (36%).
Average rainfall in September
Williston, South Africa
- Average rainfall in September: 5mm
The wettest month (with the highest rainfall) is January (21mm).
The driest month (with the least rainfall) is November (3mm).
Average rainfall days in September
Williston, South Africa
- Average rainfall days in September: 3.1 days
The month with the highest number of rainy days is January (5.9 days).
The month with the least rainy days is November (2.6 days).
Average snowfall in September
Williston, South Africa
- Average snowfall in September: 1mm
The month with the highest snowfall is July (6mm).
The months with the least snowfall are January, February, March, April, May, June, October, November and December (0mm).
Average snowfall days in September
Williston, South Africa
- Average snowfall days in September: 0.2 days
The month with the highest number of snowfall days is July (0.8 days).
The months with the least snowfall days are January, February, March, October, November and December (0 days).
Average daylight in September /
Average sunshine in September
Williston, South Africa
- Average daylight in September: 11h and 5min
The month with the longest days is December (Average daylight: 14h and 6min).
The month with the shortest days is June (Average daylight: 10h and 6min).
- Average sunshine in September: 9h and 3min
The months with the most sunshine are January and November (Average sunshine: 12h and 0min).
The month with the least sunshine is June (Average sunshine: 7h and 12min).
Average sunshine days in September
Williston, South Africa
- Average sunshine days in September: 26 days
The month with the most sunshine days is May (27 days).
The month with the least sunshine days is February (21.8 days).
Average UV index in September
Williston, South Africa
- Average UV index in September: 4
The months with the highest UV index are January, February, November and December (UV index 6).
The months with the lowest UV index are May, June and July (UV index 3).
Average cloud cover in September
Williston, South Africa
- Average cloud cover in September: 14
The month with the most cloud cover is June (Cloud cover 20).
The months with the least cloud cover are January, February and March (Cloud cover 10).
Average visibility in September
Williston, South Africa
- Average visibility in September: 10km
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).
Williston, South Africa
Weather forecast for your location
2. Allow the app to use your location
