We do need to be cautious about assuming a 16C+ is nailed on for September. Even with this notable 18.2C to 11th, we still need 14.8 daily for the rest of the month to secure a 16. That is based on current HadCET reporting back, which of course is some way above what tends to happen. I do hope these regular, nay, constant downjustments are not just designed to cover up warming. Luckily GW is able to track closer to the truth as the month moves on.

Originally Posted by: Bertwhistle

We do need to be cautious about assuming a 16C+ is nailed on for September. Even with this notable 18.2C to 11th, we still need 14.8 daily for the rest of the month to secure a 16. That is based on current HadCET reporting back, which of course is some way above what tends to happen. I do hope these regular, nay, constant downjustments are not just designed to cover up warming. Luckily GW is able to track closer to the truth as the month moves on.

If I remember correctly there is a -0.2C adjustment made each month to allow for increasd urbanisation of the sites. Not a "cover up" but a way of getting consistency across the whole series going back into the Manley data from 1659

Met Office Hadley       17.9c       Anomaly      3.5c provisional to 12th

Metcheck                    17.01c     Anomaly       3.28c

Netweather                 17.82c     Anomaly       4.13c

Peasedown St John     17.17c    Anomaly     2.89c.

Originally Posted by: Gavin P

Thanks ART! 

The decline has begun! Wonder where it will end up?

A Sepetmber CET in excess of 17C would be amazing. A September CET in excess of 18C would be truly amazing.

But look at December 2015 - A CET in excess of 9.0C Now that was incredible.

So these days anything is possible.

Originally Posted by: Saint Snow

 

 

The next couple of weeks seem to look pretty stable in terms of max & min temps, with almost all days looking like having a CET of between 13c and 15c. If the rest of the month averaged about 14c, we'd be looking at a final figure of 15.5c - 16c (depending on downward adjustments).

I'm pretty confident this will be the case - barring any crazily anomalous spell not currently showing

This evening, the GFS Ens mean line is mostly > a degree above the black line, sometimes as high as +3 and only  reaching +0 on about two occasions.  This should give CETs at the higher end of your estimate.

I continue to be baffled by the black line- start and end of run just about the same, despite two weeks of autumnal onset. 

Originally Posted by: ARTzeman

Met Office Hadley        17.6c       Anomaly       3.3c provisional to 14th

Metcheck                     16.73c     Anomaly       3.01c

Netweather                  17.52c     Anomaly        2.83c

Peasedown St John     17.0c      Anomaly       2.72c.

Still very impressive and we're half way through the month.

Met Office Hadley        17.3c      Anomaly     3.2c provisional to 17th

Metcheck                     16.48c    Anomaly     2.76c

Netweather                  17.27c    Anomaly     3.58c

Peasedown St John     16.6c     Anomaly     2.39c.

Good afternoon. I have been away on holiday for the past week so not had a chance to post any updates for a while.

Latest CET estimate for September is 15.77C. So a steady fall off for the rest of the month as would be expected. Temperatures should stay slightly above average until the final three days of the month, mainly due to mild nights. Final September CET could be very similar to August.

Despite the fall off in the CET in the second half of the month this could still be the 7th warmest September on record. The CET has reached 16C or more on 6 occasions in September. We have never had a 15.8C or 15.9C September.

Chart 1

Chart 2