August 2021 Weather report

 Overall the month was notable for very high overnight temperatures, low daytime temperatures (balancing out to an average 0.78C higher than the long-term mean, using BoM data).  Thanks to the system which came through late in the month - apparently a 'bomb low' not an East Coast Low' rainfall was very high.  Of particular note was the week of very ordinary weather near the close of the month, discussed in this post.

Rainfall

To say the least the rainfall was unevenly distributed through the month.  I was beginning to wonder about the word 'drought' but such thoughts began to shift towards 'flood' from the 23rd onwards.

Overall my Weather Station (WS) ended with 145.8 mm, somewhat more than double the median fall for August.  Looking back through records BoM (which for rainfall usually agrees quite closely with WS) only has two Augusts with higher accumulations (1990 and 2008).

As might be expected the falls have given a fair uptick to my prorata estimate of the annual fall.

Temperatures

Taking the anomaly as the overall measure of temperature we ended the month at +0.78C.

In calculating the anomaly I also classify the days as to whether the maximum or minimum are above or below average.  In August it took until the 29th before we recorded a day in which both extremes were below average.  23 of the 31 days had one of the extremes below average and the other above average.

My other approach to overall weather is to chart the daily extremes.  First the BoM data against the long term average.

...  and then the extremes from my WS.

The patterns are broadly similar.

Minimum temperatures

In a word (or two) "above average".  Here is a comparative chart.

A time series of average minima resemble a cross section of the Himalayas, with no significant trend.

Maximum temperatures

As might be expected from the comments above the mean maximum was a little below average.  This is to be expected when the sun was not seen for 7 days!  The average for 2021 was - to 1 decimal place - the same as last year.

Charting the time series again gave a profile close to that of a hilly stage in the Tour de France.  The fitted trend line had an R2 of 0.0001: ie the slope of the line  is almost 0.

Humidity

The chart of the two standard time humidities is interesting in particular for the values on 23 August (arrowed).  In the morning humidity was quite low (44% WS) but the afternoon reading had shot up to 92 %!  These numbers almost exactly match those from BoM for that date, which also shows a wind-shift from NNW at 0900  to SW by 1500 as a front, presaging the week of gloom, comes through!

In the next two charts the average  is the average of the monthly values from my WS, as BoM don't publish time series of humidity values in their free list.   For both standard times this year was below last year and just about average.

Wind

Most days were fairly calm with the rainy week having the worst wind.  Even then the longest daily run (259 km) was only the 40th long, of the 933 days for which I have a record.  It was the combination of wind, cold and rain which made this period seem so rotten.

Again, the average value all comes from my WS.

Wind direction is not currently available from my WS as something has gone wrong with with the weather vane and I need to pluck up courage to take off the cover and see what is occurring.  Nesting arthropods is suspected.