Wednesday, 7 October 2015

September 2015 weather

The main point of interest in the weather this month was the dryness.  So for that reason alone we'll start with the Precipitation.

Rain

I was surprised to find we had received as much as 10.6mm as most of it (6mm) fell on a day early in the month.  It was the least we had recorded for any September and the 6th lowest recording over the 105 months for which I have been keeping records.  It is likely to be the shape of the next several months, as indicated by this graph from the Elders website
The Bureau of Meteorology state that an El Nino event is well under way "Most international climate models surveyed by the Bureau of Meteorology indicate El Niño is likely to peak towards the end of 2015. Typically, El Niño is strongest during the late austral spring or early summer, and weakens during late summer to autumn."  That accords with the name of the phenomenon referencing the birth of a boy child in Bethlehem around 2015 years ago on December 25 (although of course it wasn't called December then).

Roll on March!

Temperatures

In terms of temperature it was a very pleasant month, with maxima just getting into the 20s on 5 occasions and cool overnight (9 readings below zero and a further 9 in the range 2oC to 0oC).
As would be expected the 00:30 and 23:30 readings are clustered around the low end of the daily ranges.

Looking at the graphs for maximum and minimum temperatures shows September to have been a little cooler than the recorded average but essentially on the normal track.

Humidity

Again right on track.  The average 15:00 reading was a little lower than last year, and as expected, a lot lower than the August 2015 reading.  
I was struck by the failure of the humidity to rise above 80% in this month.  That is not unprecedented but is a bit unusual.  However I don't have enough data to pursue that thought any further!

Wind

Somewhat of a curates egg of a month, with a few very windy days and quiet spells between them.
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 Overall this comes out to being a below average month for windiness.


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