Finally the hot weather has arrived with a sizzling end to May. But will the dry, hot and sunny weather predominate through June? Early indications suggest quite a cool start to June before things start to return to average.

The deadline for CET entries is 23:59 on 31 May. Entries will be accepted up to 48 hours late but with the usual penalty regime applied for those who are participating in the annual competition.

Please place your June CET predictions in this thread

Historic data summary

Here is the usual rundown of historic data. The June CET has not been below 13.8C since 1991 when it was only 12.1C. Last year saw the coldest June since 1991 but it was only 0.3C below the 1971-2000 average. The June CET has been 1C or more above average 7 times since 2000.  
 
Long run averages:
1971-2000: 14.1C
1981-2010: 14.5C

Here is a chart of the June CET since 1961 with a 10 year moving average



Here are some details of what the models and forecasters generally are saying at the moment

GEFS 
http://www.wetterzentrale.de/pics/MT8_London_ens.png

Well below average for the first few days before returning to average

ECM ensembles (De Bilt)
http://www.knmi.nl/exp/pluim/vijftiendaagse/index.html

A similar pattern to GFS although a little less marked. A chance that it could turn very warm again towards the end of the first week

Weatheronline
No long range forecast issued since 12 May

Netweather
http://cdn.nwstatic.co.uk/images/lrf/may12/junetemp.png

Slightly above average in the SE of the CET region, significantly above average in the far NW

Met office
http://www.metoffice.gov.uk/media/pdf/0/i/A3-plots-temp-JJA.pdf

Close to average although the spread of data points lies slightly below the 1971-2000 mean

Pattern matching (just for fun)

The CET for the first 5 months of the year will be about 7.3C. Looking at years since 1950 with a CET of between 6.7C and 7.8C for the first 5 months together with an April CET of 8.2C or less and May CET of between 11.3C and 12.1C we find the following:

1950 Jan-May 7.2C, Apr 7.6C, May 11.3C, Jun 16.2C
1971 Jan-May 6.7C, Apr 7.9C, May 11.6C, Jun 12.4C
1973 Jan-May 6.7C, Apr 7.0C, May 11.4C, Jun 14.8C
1976 Jan-May 7.1C, Apr 8.1C, May 12.1C, Jun 17.0C
1988 Jan-May 7.3C, Apr 8.2C, May 11.9C, Jun 14.4C
2000 Jan-May 7.7C, Apr 7.8C, May 12.1C, Jun 15.1C
2012 Jan-May 7.3C, Apr 7.2C, May 11.7C, Jun ?

There are three other years worth considering where the May CET was somewhat a bit cooler than this year but otherwise were quite similar years:

1967 Jan-May 7.0C, Apr 7.7C, May 10.4C, Jun 14.0C
1974 Jan-May 7.3C, Apr 8.2C, May 11.0C, Jun 13.9C
1994 Jan-May 7.0C, Apr 8.1C, May 10.7C, Jun 14.5C

This shows that for slightly cooler May's the following June was about average. For slightly warmer May's there is not much of a pattern really with a number of average years but also a couple of much warmer years and one very cool year.

Interestingly 1976 has shown up in the pattern matching this month although I think the chances of something similar happening this year are quite low. 

Best guess based on the pattern matching is for a June CET somewhere between 14C and 15C (i.e roughly average to 0.5C above average) with a small chance of a very warm month 

Edited by user 27 May 2012 16:04:21(UTC)  | Reason: Not specified

I'm thinking we could see alternating cool and very warm/hot periods with fairly breif transitional periods in between.

Overall I'm predicting guessing hoping that the hotter spells will substantially override the cooler spells to give a considerably warmer than average month with a final CET of 15.7°C

14,4c for me thanks

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gary

14.2C for me please

15.3 please

A bit of a mixed month, I think, but ending a little above average at 14.9c

Edited by user 28 May 2012 13:51:34(UTC)  | Reason: Not specified

Due to the large fluctuations in the prospects for June at the moment, there's a high chance that I'll have to revise my CET guess - I apologise in advance

13.9 for me please