Friday, 3 April 2015

Weather of March 2015

This post will stick pretty much to March weather.  I hope to take a further look at where to draw the boundary between Summer and Autumn a bit later, but will say that I am currently favouring extending Summer to the end of March.

Rain

What is this thing called rain?  We managed 16mm in 3 dribbles over the month.
 The graph clearly shows that it was way below last year's total and the 8 year average.   However the lowest rainfall for March was 14.5mm in 2013 (and if the 202mm of 2012 is excluded the average drops from 64mm to 42mm!)  So while not good perhaps it isn't too bad.

The 12 month moving average rainfall ...
... which should knock out seasonal factors, has headed South again although the 4th order polynomial looks to be recovering still.  Possibly that is getting too artificial to make much sense.

Temperatures

A reasonably warm month with 2 maxima over 30 and another 5 over 29.  They are a major reason why I mutter about it still being Summer.
The top of the green bar is the maximum temperature and the bottom is the minimum.  To my mind this chart shows a series of warming spells with a drop after each concluding with a day over 30oC on the 21st. After that date there is only one maximum over 25oC and several under 20oC.  Perhaps the equinox is important!

A second point which struck me about the chart was the relatively wide range of temperatures.  This led me to look at the average range which was 16.71oC compared with approximately 14oC in January and February this year.  I will try to do something more on temperature ranges in a later post.

The next two charts show 2015 monthly and average temperatures for each month.

The maxima average out to average, while the minimum is way cool: the lowest recording of +0.7oC contributed to that outcome (as well as sorting out some vegetable crops).

Humidity

As might be expected from the low rainfall it was a pretty arid month.The daily 3pm readings fluctuate a fair bit...
 .. but the average was barely over 40%.   This is much lower than last year, the 3 year average value and the other two months of this year..

Wind

As usual the maximum daily gust readings look like a badly sharpened saw.
 Looking at the average of gusts for each 30 minute period through the month shows it to be a somewhat still month (especially for one containing an equinox which is often regarded as a windy period).

No comments: