Weather Report January 2024

 A rather strange month with overall temperatures moderate, but warm early and cool latter, and a good serve of rain - but only on a few days.

Rain

My weather station (WS) recorded 119.2 mm of rain in January 2024.  This is 236% of the median fall, which was a little surprising in view of the current El Nino status.  However, it appears that our weather - and that of much of Australia is being more influenced by factors linked to the Antarctic than the Pacific phenomena measured for El Nino.

We had >0.2mm of rain on 8 days in the month.  This is just below the long term median number of rain days (8.5 days) but well below the median for the last 10 years.

At this early stage in the year the multiplier involved in my pro-rata estimate are large so a decent fall leads to a very high - unbelievable - estimate for the year of 1,700mm at the end of January.    However if we get no more rain by mid February the estimate drops below 1,000 mm!

Temperatures

The overall measure of temperature  the anomaly represented by the difference between the average temperature for the month and the long term mean for the month ended as +0.55C.  A chart of the development of the anomaly through the month  shows it indicating a very warm early period followed by a gradual cooling.

The next chart shows a time series of anomalies.  Interpretation of this series is above my pay scale!

The interplay of the extreme temperatures shows the very variable daily maxima and the gradual cooling of the minima.  (A fair representation of the number of blankets I needed overnight!)

Minimum temperatures

The average minimum for the month was somewhat above last year, and well above average.

Eyeballing the time series of average minima shows the series fluctuating a lot.  It is thus not surprising that there is not a significant trend.  

In terms of daily variations from 'normal', the minimum was more than 1 SD above the long-term mean for the month on 7 days (mainly early in the month) and only once (the lowest minimum at 12.6C on 27 January) more than 1 SD below the long term mean.

Maximum Temperatures.

The average daily maximum was well above January 2023  and almost exactly at the long term average for January.

A time series, with adjustment prior to 2019 to allow for differences between the BoM site near the airstrip and my WS shows much variation. There is no significant trend.

I also compiled a chart for years ending in June to avoid January being a lone point, and restricted it to the period for which I have WS data.  It shows that thus far this (financial) year is generally warm.

Humidity

An interesting month in terms of matching with rainfall and where it fits within my previous January data (only WS - BoM is very poor in terms of freely available humidity data).

In general terms the peak humidity reading indicates when in the day the rain fell.  For the 8th/9th the rain fell through the day (so both rH are high); on the 17th it was afternoon rain;  and 25/6th the rain started in the afternoon of the 25th and stopped early morning on 26th.  I shall try to follow up on this in coming months.

The 0900 reading was closer to the last two La Nina years than the earlier years ....

... while the 1500 reading was much closer to the two previous years.

Wind

A few quite drafty days!  

The run of 436km on the 7th was the 8th longest run, of 1816 days, I have recorded at my WS.  the modal run was probably around 100km giving a mean of 131km, which is very close to the long term average.  (For some reason unknown to me 2021 was only 113km while the other 4 years are all in the range 130 -137 km.)