Earth’s upper atmosphere is affected by space weather from above and terrestrial weather from below. When the upper atmosphere’s composition and winds are altered, it impacts the plasma density of the ionosphere through chemistry and movement of air. While it is well-known that upper atmosphere composition, winds, and ionospheric plasma are altered by space weather and lower atmospheric weather, it has not been well-established what the nominal, quiet-time conditions of the upper atmosphere and ionosphere are. Quiet conditions imply that there is little to no abrupt changes in space weather and that the lower atmosphere has a polar vortex (a belt of westerly winds in the midlatitudes that exists in the middle atmosphere during the winter months) that is neither strong nor weak. In this paper we examine how the ionospheric plasma density at mid-latitudes during quiet conditions varies in season, local time, and longitude. We then connect those variations to chemistry, air movement by winds, and plasma being lofted higher due to the combined affects of the geomagnetic fields and horizontal winds.