Noise assessments based on comparisons of existing or future specific noise levels against the context of existing measured noise levels depend on the assumption that all baseline data is fully representative of long term conditions. The typical variation in measured ambient and background noise levels over the 24 hour diurnal cycle is widely understood but, and depending on the relative distances from the main noise sources in the area, additional variation or uncertainty can also arise associated with differences in meteorological conditions. Particularly in rural areas, high wind speeds passing through nearby trees and foliage can generate significant contributions to baseline noise levels, while wind and temperature gradients associated with different meteorological conditions can lead to moderate enhancement or significant attenuation attributable to downward or upward sound ray curvature. This paper reports an investigation of the relationships between long term measurements of ambient and background noise levels and wind speed and direction conditions at two fixed locations, one near Birmingham and the other near Heathrow. A number of other meteorological variables such as rainfall, temperature, and humidity were also investigated but the range of variation or rate of occurence in each of these variables was insufficient to yield any interesting results.