Sunday, 1 May 2016

Weather April 2016

Very dry is the description that matters.  Our dams are the lowest I have seen, and Whiskers Creek has not run at all during the month..

Rain

We managed a miserable 4.6mm for the month with noticeable falls on 2 days (one of which was the 30th)!  This was the lowest April of the 10 years I have been recording here, and only 1.6mm above the lowest month ever (May 2009).
The pathetic nature of the precipitation is emphasised by a 12 month moving average (which removes the impact of seasonal factors.
This shows the adjusted rainfall has dropped consistently since November 2015.

Fortunately May looks somewhat better: indeed as I type, at 6am on the 1st of May we have already got 3.2mm for the month!

Temperatures

A temperate month with few hot days or cold nights.  The overall pattern was a series of sharp drops in maxima, followed by a slow warming period.  The height of each recovery was a little lower than the one before.
For the benefit of new readers the green lines link the minimum and maximum temperatures for each day while the boxes indicate the temperatures at 0030 and 2330 each day (red indicates 2330 is warmer than 0030 and blue that 0030 is the warmer).

The first frost (temperature at 2oC or less) was 1.8oC on 11 April (about average date).  Another two frosts occurred towards the end of the month. 

In terms of averages both average minimum and maximum were above the average of previous years.  The increase is higher for the maximum.

Humidity

In a word "low"!

It has been suggested that an rH of 40% is 'reasonable': in April 2016 11 days were below that level at 3pm.  Of the four previous Aprils for which I have records there has only been one previous reading that low.

Looking at the longer term average shows this month to be well below average and significantly below last April.  (The year on year comparison is not surprising as rainfall in April 2016 was the least recorded for April while 2015 was the most.)


Wind

The daily chart for the month shows a couple of moderately windy spells.
While the longer term chart of averages (taken across every 30 minute reading rather than the daily maximum gust) shows the continued low level of wind/

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