October 2023 Weather Report

After a small delay, sorry reader,  here is the weather report for October.  A rather variable month with slightly warm and wet as a summary.

Rain

After 4 months with very much below median rainfall October was 163% of the median fall for the month.  While most (70%) of that fall came in an event on 4-5 October there were non-trivial falls on 9 days.

The heavy fall (temporarily)arrested the decline in the pro-rata estimate of overall rain for the year but the dryness of the last two weeks has resumed the downwards trajectory.  As at the end of the month the projected fall for 2023 in total is 658mm, which would be the third lowest fall recorded.

Temperatures

The average temperature for the month was 0.46C above the long term average for October.  This metric (the anomaly).  There was a very hot start to the month after which the anomaly varied between close to zero and +1C.

The time series of values for the anomaly shows October to be a drop back to the recent range of usual values (although a 3-year series is way too short to make any definite statements).

A chart of daily extremes shows the maxima to have several spells of well above average values while the minima are closer to average (but with few significantly low values).

The 1st and 3rd were the only days with both minimum and maximum above the long term mean for the equivalent variables, so no heat waves or cold snaps.

Minimum temperatures

The average minimum temperature for the month was 0.4C above the long term October mean minimum.  On 5 days the minimum was >1SD above the monthly mean with 1 day >2SD.  There were no runs of 3+ days of significantly elevated minima.  Only 1 day was significantly below the monthly mean minimum.

Maximum temperatures

The average maxmimum temperature for the month was 0.5C above the long term October mean maximum.  On 7 days the maximum was >1SD above the monthly mean with 1 day >2SD.  There were no runs of 3+ days of significantly elevated maxima.  Only 1 day was significantly below the monthly mean minimum.

Humidity

The daily readings for humidity at the standard times of 0900 and 1500 show the month to be somewhat muggier than I would expect, with few 1500 readings below 50%.  However, for both values the monthly average is below average (for the 5 years for which I have data).

The only really interesting feature in the chart is 12 October with a very high 0900 reading followed by a very low 1500 reading.  This matches very closely with BoM data for the Airport which also shows a shift in the wind from North (=dry) at 0900 to SSW (= moist) at 1500.

Wind

My gut feeling was that it was a pretty windy month and the data, fortunately, backs that up.  The next chart shows the daily average hourly run for 2023 and the average of the previous 4 Octobers  It is clear that this year had longer runs on many days.

The longest run (326k, on the 21st) is the 5th longest October run (of 151 records).