Which environmental factor can affect radar speed detection accuracy?

Weather conditions such as rain can significantly impact the accuracy of radar speed detection. Rain can cause radar waves to scatter and reflect inconsistently, leading to difficulties in accurately measuring the speed of vehicles. The moisture in the air can absorb some of the radar energy or cause interference, resulting in erroneous readings. Additionally, the presence of water on the road surface can alter how the radar signal interacts with vehicles, further complicating accurate speed assessments.

In contrast, while wind speed, time of day, and temperature variations may influence certain environmental conditions, they do not have the same direct and immediate effects on radar detection accuracy as adverse weather conditions do. For example, strong winds may cause physical movement of portable radar equipment or affect debris, but they do not alter the radar waves themselves in a way that leads to inaccuracies. Similarly, while time of day can impact visibility, it does not inherently interfere with radar technology like rain can. Temperature changes might affect the propagation of radar signals marginally, but their effect is generally less significant than that of direct weather influences such as rain.