Should Weather Ever Be Considered ‘Exceptional'?

With the recent arctic blast and its after effects still reverberating, it seems a useful time to consider how weather affects the construction industry.

With most standard form contracts providing for weather issues as events entitling a contractor to an extension of time and in some instances additional money, it is tempting to treat these clauses as "boiler plate" and gloss over them.  However, with weather becoming more unpredictable globally, is that a safe stance to take?

The NEC4 Engineering and Construction Contract provides that weather measures at a specified place must, when compared to the weather data provided for in the contract, be shown to occur less than once in ten years (clause 60).