Does wind affect the temperature on a thermometer?
The answer is, "it depends." If the wind is blowing on an object which is at or near the ambient air temperature (say, a thermometer attached to the outside of the house), the temperature of the wind will be the same as the temerature of the air. Thus, the thermometer will show the temperature of the air.
If the object has a temperature drastically different from the ambient air temperature, then the wind will hasten the temperature change of the object. This is why "wind chill" works. Your skin temperature is higher than the air temperature, so when the wind blows, the moving air aids in cooling your skin, making it feel colder. In simple terms, your body warms up a thin layer of air around you. If that air escapes, your body has to warm up a new layer of air. When the wind blows, it replaces the warm air near your skin with colder air so your body has to give heat to warm up the new, cold air layer. This is, by the way, why windbreakers work. Windbreakers simply trap the layer of warm air near your body, preventing the wind from pushing it away.
So, to summarize, if the object is the same temperature as the air, wind won’t make a difference. If the object is substantially warmer or colder than the air, moving the air past the object will make the object change its temperature faster than non-moving air will.
No, wind has no effect on the actual temperature on a thermometer. However, wind can affect the way the temperature feels on your skin. As the wind blows, it cools your body. This is why forecasters report the wind-chill temperature, which is how cold the air feels to the average person at a specific wind speed. Learn more about wind chill on this USA TODAY resource page.