National Grid, the firm responsible for managing the gas transmission
network have a web page giving a daily report at
http://www.nationalgrid.com/uk/Gas/Data/dsr.

It includes a 'composite weather curve' of a measure combining
temperature and wind that they use to predict the demand for gas.

The 'warm', 'cold' and 'normal' curves are shown giving a sort of smile
shape with the minimum around 21 January. The actuals are also shown.

I've had a go at reading off the actuals since the cold turn in
mid-November to plot my own graph with a quadratic trend line. This is
shown on http://www.crowsnest.co.uk/weather06.htm.

The best fit quadratic has a negative x squared factor giving a downturn
at the ends. If you project this forward, it gives a value of -0.3 for
1st August - colder than we've seen at any time this winter.

I trust the spring upturn will appear soon!
--
Goalie of the Century