Annual Weather Report 2022

 This will be a brief summary of the weather during the year.  Most of the data will come from my Weather Station (WS) because (a) the BoM site at the Airport was out of action for a time; and (b) as the BoM Climate Data Online is experiencing "technical problems" it is more or less impossible to assess/access what data they do have.

One sentence summary!

It was a very wet year with mild maximum temperatures and relatively high minima.

Rainfall

A very wet year, with the 4th highest rainfall - 1351 mm -recorded.  The two heaviest days were 2nd and 3rd April with 144.8 and 120.8 mm respectively, contributing to the monthly total of 300.2 mm (7th highest monthly total ever recorded).

In this chart the final 4 years are WS data, the rest is BoM.

I compared the past four years with BoM totals and for 2020 and 2021 the totals were very close.  

• For 2019 (the lowest rainfall recorded by BoM at the site) the record at my WS was even lower: I suspect this was due to squalls along the coast not making it to my site.  
• For 2023 the situation is a little more complicated:
• Comparing daily records after the event (when that can be extracted for the BoM)  is made complicated by the BoM reset at 0900 each day while my WS (and I suspect) every private WS working on calendar days.
• My WS recorded 62 mm more than the BoM in December2022: without being able to check (see point b in the preamble) I assume this is due to the BoM station being offline during the major rainfall event of the month (I hope that this will be lead to the BoM eventually nullifying the December - and thus annual - records.)
• I also recorded a lot more than the Airport site during an event in April 2022 and in February and March of the year.  
• There are no months in 2022 in which BoM significantly exceeded my recorded fall
• A Nylex gauge is next to my WS and has - within 1 or 2 mm each event - confirmed the WS readings.

My conclusion is that it is more informative to use the longer BoM as an historical backdrop, accepting that it will have some inconsistencies, than to just present a 4 year series from my WS.

Days of Rainfall

As well as the amount of rain which fell the number of days with rainfall is important, especially for gardeners.  My station has a minimum recording quantity of 0.2mm, which is frequently delivered by a heavy dew: while effectively meaning there has been little evaporation such trivial "falls" do not provide soil water.  So I disregard falls of 2mm.  A meteorologist acquaintance suggested 5mm was needed to be of assistance for gardening so I have 2 metrics for rain days reflecting those limits (the numbers above the bars show the number of days covered by each bar).  

I have a series of daily rainfalls going back to 1975, but in the early parts of this period there are frequently observations accumulated over several days which makes the data useless for evaluating this metric.

Rate of rainfall

My WS records the maximum rate of rainfall in each one hour interval.  To get an easy to handle indicator out of that I use maximum rate recorded in a day.  The highest rate recorded in a day in 2022 was 240mm/hr with 2 other days recording peak falls of 118.8 mm/hr.  This next chart shows 3 groups of rates equivalent to low, medium and high rates.

Not only did 2022 have the greatest number of raindays but it had, by a fair margin, the highest number of days with a high maximum rate.

Another way of looking at rate of rain is the amount that actually fell in a one-hour recording period.  The two heaviest periods in 2022 were 1800 hrs and 1900 hrs on 3 April with 29.8 and 29.2 mm respectively.  The third highest fall was 28.6 mm on 23 March

Temperatures

My overall metric for temperature is the temperature anomaly: the mean temperature for a period minus the long term average mean temperature.  (Note[1]: I have become a little uncertain about exactly how I have calculated some of these data wrt to the maximum values applied.  I don't think the resultant picture changes much as a result, but some detailed analysis will happen, once the CDOL becomes reliably available again. [2} I have now 'regularised' the data and don't think it has altered the overall picture by veymuch.  Details available on request. )

The overall anomaly for the year was -0.04C (effectively 0!) The first chart shows the anomaly for each month of 2022.  The value for December (-0.91C is the lowest value obtained in the 4 years for which I have calculated the value for (at least most) months.  For the months with positive values (ie a warmer than usual month) none of the results are extreme: the greatest positive anomaly recorded is 2.41C in December 2019.

I have also calculated a form of annual anomaly using the difference between annual average minima and maxima compared with the 30 year average of those values.   The result is shown below.

I am reluctant to make any large statements about these data (see caveat above) but it certainly does not show a declining series.

The following chart shows the average minimum, mean and maximum daily temperatures from my WS for the 4 year in which it has been operating.

The last two years appear to have been a little cooler than the preceding 2.

Maximum temperature

The next chart shows a time series of maximum temperatures with adjustments applied to the years prior to 2019 to adjust for the sea breeze effect at the airport.

Clearly 2022 was quite a cool year in terms of average maximum temperature (19.6C vs long term average 20.5C).  This quite probably reflects the relatively frequent cloud cover due to rain events.  This blocks the heating effect of solar exposure.

Minimum temperatures

The sea breeze effect doesn't affect the minimum temperature to any extent that I have been able to determine so the back series in this chart is as recorded by BoM.  The average minimum temperature in 2022 was 11.76C against a long term average of 11.0C.

In the case of minimum temperatures the presence of cloud holds in the warmth of the day so it should be expected that a wet year has high minima.  (A scatterplot shows a positive, but not significant relationship between rainfall and minimum temperature.)  There seems to be a fairly significant increase shown by the trend line (based on a rule of thumb that r2 >0.5 is significant).

Humidity

Even when fully operational CDOL contains very limited information about Humidity (which is explainable by there having to be some limit to the data provided at no cost).  I also have doubts about the usefulness of data from the BoM site, exposed to sea breezes, to compare with my site which is both more inland and much less exposed to wind.   So I have used data from my WS to show the annual average values of rH for the two standard recording times.

Not surprisingly, in view of the rainfall, 2022 is the highest of the 4 years available on both measures.

Wind

Again very limited data available from BoM for good reasons.  I have from time to time compared wind gusts at my site with those recorded at the Bom site and concluded that overall the gusts are ~30% stronger at the BoM site, with significant variation according to the direction of the wind.  So the chart below shows only data from my site.

The average run has dropped since 2019 with the last two years very similar in run.

I have in the past looked at other measures of 'windiness' using maximum gust or average gust and found the correlation extremely high.  I favour average daily run as it includes an entire day rather than a point in time as do the gust based data.  The maximum gust recorded in 2022 was 61.2 kph similar to the previous 2 years, but well below the 72.9 kph recorded in 2019.