A 39 years of archived meteorological data measured at two stations
located in the northern and southern parts of the Quebec, Canada is used
to estimating the surface refractivity and its dry and wet components.
The results of the comparison of the obtained estimates showed that for
all months the values of the dry component are higher in the northern
part, whereas that the values of the wet component are higher in the
southern part. Due to this, for several months of the year, the values
of the surface refractivity are higher in the northern part and for the
remaining months in the southern part. Moreover, in both parts, August
is the month where the highest values of the surface refractivity were
recorded. For this month, the slope of the surface refractivity trend in
the northern is several times higher than that in the southern part.