Plus information for September
Graph1 shows: Temperatures (in red), dew point (in green), wind speed (daily max in dark blue, half-hour averages in light blue), wind direction (in red) and atmospheric pressure (in grey).
Graph 2 shows: Temperatures and rain for the month.
Weather highlights:
1 Small amounts of rain fell, especially on the 15th and 16th, when 5.8mm
fell. This helped to settle the winter dust to some degree.
2 The severe cold front that hit Benoni near the end of the month had many
typical features to its profile – these were as follows:-
On Thursday 28th, the pressure dropped to below 830hPa – this indicated a significant change in weather (see Graph 1)- The wind backed to SW and a very windy day followed, wind speed reaching moderate gale force of 54.7km/h at 14:00 on that day.
– At 06.30am on Friday 29th, the wind chill factor reached -11°C and …- At 05.01am on Saturday 30th, the wind chill factor dropped to -12°C.
