NEC4 Weather Event

We have had a weather event on one of our current projects. We understand that if the event is greater than a 1 in 10 that we would be entitled to a Compensation Event. Could someone clarify the 10 year data is from 2012-2021 if the event occurred this year, or does the data need to be from 2011-2020 ie the past 10 years? Much appreciated thanks


@Barry_Trebes @Neil_Earnshaw can you clarify for James?

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You use the weather measurements and weather data from the month in which the compensation event occurred. Your contract will state where this information comes from, usually in the UK it would be the Met Office who will provide the 1 in 10 return values so you don’t need to worry about calculating them for yourselves. If the contract states the information is to come from somewhere else then it may make things harder for you if they don’t provide it in a format that is compatible with the NEC4 approach. Met Office typically use a long-term 30-year period to assess the 1 in 10 return value by taking the worst three measurements averaged over the period. Its a rolling average which is worked back from the month in which the event occurred.

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