From Rob Gough, Montana State University Extension agent:
"Do plants feel wind chill like we do? It sure feels a lot colder to us when the wind is blowing. It makes 30° feel like 0°. Meteorologists express this feeling by the term 'wind chill' and we often hear wind chill advisories on the local radio station. Do plants feel wind chill? Does a wind chill of 25° below make the plant react as though it were that cold?
The answer is in the word 'feel.' The term 'wind chill' was developed to express how the combination of wind speed and temperature 'feel' on exposed skin. The skin has nerves which transmit that feeling to the brain and we say, 'Boy, it sure feels a lot colder than 30 degrees with all this wind.' But the plant doesn't feel. It has no nerves to transmit that impulse. So to use the term 'wind chill' in relation to plants is meaningless. But that's not to say that wind and cold do not affect plants. Last time I told you how cold influences plants. Wind plays an important role too. Wind can increase the evaporation of soil moisture, thus speeding drying and making water harder for the plant to come by. Wind also speeds evaporation of moisture from the plant surface. Even without leaves, deciduous plants can lose moisture through their young bark. The faster the wind, the faster moisture is lost.