It was a perfect evening for football: cloudless skies and a light fall breeze.

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But there might be an even more animalistic explanation why a cloudless sky buoys us up: "When it's good weather there's much more flesh on show, which cheers most people up, " says Dr Workman.

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Mary Woolnoth on a cloudless day.

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The sky is still a perfect cloudless blue and the forecasters have dropped their previous prediction of rain by the weekend.

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But a clear, cloudless day-time sky is blue because molecules in the air scatter blue light from the sun more easily than they do red light.

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