Weather

The 1893 flood was the result of the heaviest rainfall experienced in the district and in south east Queensland when 35.71 inches fell at Crohamhurst in 24 hours. This was recorded by Inigo Jones and was Australia’s highest rainfall within a 24 hour period. The total rainfall in the episode amounted to 78 inches, resulting in the great 1893 flood in Brisbane. Rain on Bald Knob flows down London Creek to the Stanley River and Somerset Dam. Bald Knob rainfall is thus a very important source of water for Brisbane. Heavy rainfall on the plateau and ranges can cause flooding in the Stanley, Brisbane, Mooloolah, Maroochy and Mary Rivers.

In Harden (1939), the meteorologist Inigo Jones described the comparative rainfall records.

“At Esk on the Brisbane River the average annual rainfall is just under forty inches, and at Kilcoy is just over forty. At Woodford it has risen at the rate of an inch a mile to fifty-two. At Peachester it is nearly 68, having risen two inches per mile and at Crohamhurst it is just on seventy six, rising from Peachester nearly three inches per mile. At Bald Knob, two miles distant, the average is now ninety inches which is a rise of seven inches per mile and this average is only for the last 10 years which was a notably dry period. In the wettest year, 1931, Crohamhurst recorded 98 inches and Bald Knob 114 inches.”

If Bald Knob had a weather recording station in 1893 it may now hold the record for the highest rainfall ever recorded over 24 hours in south east Queensland. A weather forecaster from the Commonwealth Meteorological Bureau confirmed that Bald Knob would have had at least as high a rainfall on that date as Crohamhurst and more than the recordings of nearby stations, Mooloolah and Landsborough.

The average annual rainfall recorded at the Bald Knob weather recording station is 2034.7mm (80.11 inches). The highest annual rainfall was 3837.4mm (151.07 inches) and the lowest was 784.8mm (30.89 inches). The only areas in the south east of Queensland which receive higher average annual rainfall are the mountainous areas near the New South Wales border, Springbrook’s annual average is a little over 3000mm.