Mallacoota weather report July 2026

 Always good to adapt a line from The Bard, in this case,  “Romeo and Juliet”:

“Nino, Nino, wherefore art thou El Nino?”

There have been a lot of mutterings in the media about the likelihood of a strong El Nino event this year.  BoM has an interesting explainer.  The interesting issue with El Nino is, as I understand it, is that it has 2 more or less linked meanings:

1. The name was sourced from community observations of very dry periods around Christmas - hence the name El Nino (the boy child in English), a reference to the birth of Jesus.

2. Climatologists have found that these events often coincided well with temperature phenomena in the Pacific.

However I believe that as the temperature effects do not always match the observed weather across the globe it is a matter of correlation rather than causation.  So what the media have been saying is that we can expect a hot dry Summer.  

Although we are still some months from Christmas I suspect the current dry, warm weather is pointing the way towards a hot dry Summer.

A note on data

As my Davis Weather Station (WS) was beginning to fail in March I acquired a new, cheaper, WS under the Ecowitt brand.  That has been a great success passing all the data checks I have applied to it. It is also brilliant being able to access the WS when in Melbourne.

However on the 21st I noticed that the system appeared to stop recording data when I turned the light on the console off when going to bed..  I sent an email to Ecowitt Australia and got a same-day response suggesting the likely cause of the issue, how to diagnose this, and some solutions.  I followed the suggestions and it has now resumed correct operation.

Very pleasing level of support.

Rainfall

As implied in the preamble this month has continued the generally woeful performance of the rain gods this year.  The total monthly fall was 25.3mm at my WS (validated by 26.4 at BoM Airport).  That was 34% of the median July fall.  Of the monthly fall 43% was provided by the 10.9mm on the 14th.

The pro-rata estimate of the annual fall shows it to be well below recent years, and the trend line of the series is looking most unhappy.

As would be expected from that tale of woe this month was well below last year and the average.  Looking at my past records (including falls at the airport site) there are only 4 (of 48) lower July falls, and 3 of the last 4 months have been well below median for the month.

Temperatures

The weather anomaly ended the month at +1.17o C.  After a rather warm start to the month the temperatures moderated somewhat.

A time series of values of the anomaly shows the moving average continuing upwards, while the trend of the moving average is on a downwards trajectory.  Interesting but I am not going to punt the farm on that evidence!

Looking at the daily extremes (see page in Google Sheet) shows that most values were above average, especially for the maximum series.  It was not until the 29th that both measures were below average on the same day (on average there would be 11 days on which that was the case.  This will be discussed in more detail below.

The daily range of temperatures was somewhat larger than average on 21 days with some very high values including 16.1o C (from 3.7o C to 19.8o C) on the 28th.

As the comparison with the average was so biased towards higher temperatures I compared the daily extremes for my WS and the BoM Airport site. 

The maximum series for my WS is a bit higher than the airport which is expected due to the cooling effect of the ocean and particularly the sea breeze at the airport site.  However the patterns are very similar, confirmed by a correlation coefficient of 0.84.  The minima are very similar except for the 31st where the WS minimum occurred at 2300hrs and is thus counted against 1 August by BoM due to the 🤬 0900 reset.  My overall conclusion is that the WS data are sound.

Minimum Temperatures

The average minimum for the month (7.12o C) is in the middle of the sets of data for the years from 2019 onwards.  The lowest temperature was 2.6o C on the 19th.

 

4 of the minima were significantly below the monthly average and 5 were significantly above.  None of the values were very significantly different to the monthly average.

Maximum temperatures

The average maximum for the month (17.26o C) was the highest July average maximum recorded at my WS since 2019 (or in the much longer series including the BoM Airport).  This is shown in the next chart. The highest  temperature was 22.6o C on the 13th and the lowest maximum 13.2o C on the 5th.

2 of the maxima were very significantly above the July average maximum and a further 10 readings were significantly above.  Only the lowest reading was significantly below average.

Humidity

As for last month I have used 0600 hrs as my standard morning time and 1400hrs as the standard afternoon time.  The daily values are shown in the following chart.

The abrupt drop on the 13th seemed somewhat anomalous so I have checked the reading for the Airport which show a value of 40%rH for 1500hrs on the 13th which allowing for the difference in location and wind exposure I see as quite comparable with the 30% recorded by my WS.  I have also downloaded the detailed (every 10 minutes) readings for the day by my WS.  These are presented in the next chart showing the steady drop in humidity through the day.  Again this indicates the WS data is sound.

Wind

The first chart shows the average and maximum gust for each day.  They correlate rather well.

The second chart compares the maximum gust for this month, June 2025 and the average June gust since 2019.  The month is very close to average.

The final wind chart is a snip from the Ecowitt system showing the direction of the wind at each of the 6 hourly readings using the Monthly protocol.

Solar

I am still working out how to analyse and present the information on solar radiation.  The first chart is pretty straightforward, showing the total watts per square metre of each day of the month.  I have added a linear trend line as it looked as though the raw series was sloping upwards. The value of r2 supports that view to a weak extent.

The second solar chart took quite a bit of mucking about to extract data for each 10 minute period and sum that for each hour for two days.  The total watts for the 4th were 1182 and for the 25th 1530.  It would seem that cloud came over around noon on 4th and a little earlier on the 25th but the latter day returned to sub\nshine.

some heath-haunting flowers (and some birds)

It being a nice day weatherwise we took ourselves off to the Davis Beach Heath to see how the flowers were doing.  Not exactly a carpet of colour but few pretties here and there.

The last couple of Springs have not been glorious floriferousness, so we have got out of the habit of identifying plants.  Which only means one thing: we have forgotten most everything. But here are some OK snaps.  I shall try to attach better names soon(ish).

Acacia suavolens

Acacia myrtifolia

A pea!

Possibly a different pea!

Allocasuarina nana (or possibly another Allocasuarina)

Comesperma volubile

Billardiera 

Goodenia ovata

Later in the afternoon I went to the Narrows Car Park to see how many Night Herons I could find.  The answer was 4: 3 flushed into the big eucalypt and one remained lurking in the Pittosporum.

This one shows a faint trace of a plume on the head.

On the way home I was impressed with the pink bill on this Pelican (and a few others of the species) in the Lake at Mullet Creek.

 

Weather Report May 20206

 The overall weather for the month was very warm and a tad above average for dampness.

Rainfall

After the very dry April it was good - apart from the lawn growth - to get a fall of 76.8mm (102.8% of the median fall for May).  It was also spread well across the month.

By the end of the month my pro-rata estimate for the year was 951mm, well below last year and similar to 2024.  

It seems that some long-range  forecasts are still talking about an El Nino taking effect in the coming months but the word from the BoM seems to be taking 20c in several directions (similar to "2 bob each way" but lacking that level of certainty).  

Temperatures

The temparature anomaly ended the month at +1.84^o C.  Through the month the series was always above 1^o C after a very high value at the start of the month.  (This is discussed more under the 'maximum' subheading below.)

Looking at the historical values of the anomaly this was among the higher values recorded and leads to a slight uptick in the moving average series.

In terms of extreme temperatures the daily series shows quite consistent values above the average for the date. 

I compared the values from my WS with those from the BoM station at the Airport.  Allowing for the known differences between the sites (IMO mainly due to wind exposure)the picture is very consistent.  

Minimum Temperatures

The average minimum for the month was 11.04^o C which is 1.6^o C above the long term mean and nearly 1^o C above the next highest monthly average.   Of the top 25 May minima 6 were recorded in May 2026, while 3 would have been expected: in view of the foregoing it is not surprising that the highest minimum for the month (17.8^o C on the 3rd) was the highest minmum recorded.  At the other end of the scale the lowest minmum (6.1^o C on the 22nd) was only the 16th lowest recorded.

Not surprisingly, in my time series this year is much above all other years of WS records.

Only 1 minimum was significantly below the monthly average but 9 were significantly above average and a further 3 values were very significantly above average.

Maximum temperatures

The average maximum for the month was 20.16^o C, 1.17^o C above the average maximum for May.  To my surprise it was not the warmest May which award goes to 2007 at 20.27^o C.  (In 2007 again there were many days above 20^o C but no outstanding result such as might cause me to doubt the value recorded.  The warmest day this year was 24.6^o C on the 26th.  Looking at the history of my weather station readings the daily maxima are not dramatic - the highest reading is only the 8th highest -but a high proportion of the hotter days were recorded this year.  (Of the 25 hottest May days, 8 were recorded this year.

The time series shows this year to be above the 7 other years for which I have WS data, but not as much as for the minmum series.

3 minima were significantly below the monthly mean value, 4 values significantly above the monthly mean value and an astonishing 16 values were very significantly above the  monthly mean value.  On examing the historic series it appears that the maxima for the month do not vary as much as other months (the relative standard deviation for May is 4.7%  whereas for March it is 6.4%).  My knowledge of meteorology is too limited to explain why this is so.

Humidity 

I have discussed the issue of standard times in the report for April, being the first month with my new WS.  I have taken the standard times as 6am (representing morning values) and 2pm (1400hrs, representing afternoon values).  In general terms this is sufficiently comparable with the BoM, administratively driven stds of 9am and 3pm.

For this month the most notable feature is the high values of the afternoon readings.

The morning reading for this month is well above - 2.1% points -  the average (since 2019).

For the afternoon reading this month was on average was 4.4 percentage points higher than average and from eyeballing the daily chart above would have been even higher withough the drop in the last 2 days of the month.

Wind

With the new WS I no longer have a measure of 'run' (although I muight investigate ways of estimating that when time permits) so have used two measures of gusts as my indicator of daily windiness.

The monthly gust chart below is a little worrying as both months with the new WS appear well above average, suggeting the change is due to the new WS.  We shall see, but do not sell the farm (nor the boat) on the basis of this chart.

Solar

Only available for the last two months so all I will offer is a measure of total daily watts.

The 2 prominent peaks in this chart coincide exactly with days in which the measures of cloud cover cited on the BoM site (compiled at Gabo Island) were very low.  I shall try to work out a way of charting this in the future but initial results are far from optimistic.

Lightning

I again use data from a friend's WS reporting to the Tempest Network which gives the number of strikes estimated within 40 km of the Mallacoota Wharf.  It is graphed below using a logarithmic scale to accomodate the very large number of strikes in February 2025.  265 (= log 2.42) strikes were recorded in May 2026, a relatively high number for May.  

Weather of 7 May 2026

The Indian Summer which began the month has definitely finished.  I won't be lighting a fire today - the house is still warm inside - but it is definitely more like Winter than Summer.  Here is the BoM radar image about 1410 hrs.

It has also been a bit noisy with lightning strikes shown on this image.  White circles are very recent, red crosses are the oldest.

An image from the Ecowitt software on my Weather Station.  The lowest temperature (so far, as at 1418hrs) has been 5.7^o C with a maximum of 11.7^o C.

I don't think the water heater nor solar panels are helping much at present!

Total rain is now, 1424 hrs, 10.6mm, which will be doing some good.

I have just seen a post from BoM mentioning snow at reasonably low locations, of which the closest to Mallacoota was Bombala where the War Memorial in the centre of town is at 704m AMSL.

Insects on Camellias and other garden plants

 Frances alerted me to there being interesting insects on our full-flowering Camellia.  Of course this included a good number of European Honeybees.

But as Frances advised there were other species.  The first was what iNaturalist has suggested to be  Leptomyrmex erythrocephalus, the Red-headed Spider Ant.  It has a red head and looks like both a spider and an ant!

The third species was (again suggested by iNaturalist) Polistes humilis, Australian Paper Wasp.  I picked it as a wasp of some form, from the narrow waist.

Let us see how other experts go on confirming (or otherwise) these names.  There were other insects around - my first guess is Hoverflies - but they were not cooperative in posing.  I shall try again.

I failed again on the Hoverflies but a nearby Daisy attracted a small bee for which Genus Exoneura (Reed Bees) was suggested.

The next one wasn't on a plant but one of our sliding doors after dark.  It fell off the door and vanished before I could get a dorsal image.  iNaturalist has suggested Paracaedicia serrata (Serrated Bush Katydid) as the ID.