When fog forms below 0C, its super-cooled water droplets remain liquid, even though the temperature is below freezing.

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This latest research, including the decade of stalled temperature rises, produces a range of 0.9-5.0C.

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Race temperatures reached 40C during the day and dropped to 0C at night.

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But it was minus 11 0C at noon (yes, very cold for here) and there was no appreciable wind that could be felt.

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Temperatures across the UK on Tuesday range between 0C and 4C but forecasters said sleet and snow could result in icy stretches overnight into Wednesday as surfaces froze under them.

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Martin Siegert points out that the water in the drill head will only be a few degrees above 0C as it enters the lake - it inevitably cools as it flows 3km down into a hole that is surrounded by ice at -35C.

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