Sadly, I think that’s too big an ask.  We only have four days to go and at this stage of the month it takes a big change in temperature to make much difference to the running mean. 

If only we hadn’t had clear night skies last week, bringing the low minima.  

The daily estimated means based on latest output for the rest of the month are 16.6C, 16.7C, 14.7C, 15.4C, 12.9C, 15.1C, 14.4C. 14.1C, 13.9C, 13.9C.

 The downward adjustment tends to be quite large when we have cold nights. So I would not be surprised to see an adjustment of as much as 0.4C.

Hence a final CET just under 14C looks most likely at present. Hence I am quite happy with my prediction of 13.8C. 

Hadley for this period gives, as expected given likely downjustment, mostly a little above these projections. Accurate stuff GW!

The fly in the ointment was the 16.2 aot 12.9 on 25th. A cloudy night? 3.3 difference gives a potential 0.1 end month difference.

As a consequence,from 21st to 25th the HadCET provisional pre-downjustment is 5.5C above these predictions, an average of 1.1C. 

I reckon a 14+ is still on, but we'll need the warm sectors to align with night-time!

This is nail-bitingly good. I won't be among the month leaders but could still end up with a narrow miss for the month. 

I didn't know that, why is that, surely the max temp on Sep 30th belongs in the September CET?

No, honestly.  For once, I was being serious and I’m sure this has been explained before.  To me it makes sense (just) if the daily means are calculated from 9am to 9am.  

You're right I remember discussing this before and I was trying to remember what it meant !

I think all it means that on any given day the "snapshot" of maximum and minimum temperature is taken at 09:00 on the following day with respect to the previous 24 hours from 09:00 on day 1 to 09:00 on day 2

In a period of (say) rapidly rising temperature during a sudden thaw after a cold spell, the minimum temperature used at 09:00 on day 2 may be from 09:00:01 on day 1