Seasonal Normal Review - December Update

The latest update from Xoserve's Demand Estimation team on the Seasonal Normal Review.

Published on 18 Dec 2019

Our Demand Estimation Team is pleased to provide our customers with our second update on the industry’s Seasonal Normal Review.

In October, we shared progress with our customers which contained an introduction to the Seasonal Normal Review and Composite Weather Variable, updates on the key industry milestone we achieved at that stage, and a look ahead to next steps.

We’d recommend familiarising yourself with our October update before reading our latest December update.

Our latest Seasonal Normal Review update provides information on the final industry milestone that we have successfully passed. Further updates will be provided during 2020 when more information is known about the likely impacts to key data items such as the Annual Quantity (AQ) and Supply Offtake Quantity (SOQ).

Seasonal Normal Review - October Update

Last updated on 24 Oct 2019

Seasonal Normal Review - December Update

Last updated on 18 Dec 2019

What is the Seasonal Normal Review, and why is it important?

The ability to estimate gas consumption is critical to a range of calculations across the gas industry. These may be at a daily level such as Non-Daily Metered (NDM) allocation, or at an annual level such as Annual Quantity (AQ) calculations. They can even be at a theoretical level, for example when trying to estimate the peak consumption of gas during extreme cold weather events as part of Supply Offtake Quantity (SOQ) calculations.

Every day consumption goes up or down and there will be many reasons why, some of which are complex and some are more predictable. Unsurprisingly gas consumption has a very strong correlation with weather and consequently, many years ago, the industry created its own unique weather data item which is designed to explain this key relationship - the Composite Weather Variable (CWV).

The Composite Weather Variable (CWV), which represents actual weather, and the Seasonal Normal Composite Weather Variable (SNCWV), which represents the industry’s view of ‘normal’ weather, help us estimate gas consumption throughout the year.

To ensure these data items continue to provide the industry with an accurate reflection of gas consumption across the year, our Demand Estimation Team is overseeing the ‘Seasonal Normal Review’, a deliverable focussed on the suitability of the CWV and SNCWV to represent latest gas consumption behaviours and levels.

Read our latest update and find out more

You can read the full update here, and you can also find more information on the work of our Demand Estimation Team, including frequently asked questions on key topics, on the Demand Estimation page of our website.

If you have any questions or comments on the Seasonal Normal Review, please contact us at