Measurements of nitric oxide at 105 km by the ultraviolet nitric oxide experiment on Atmosphere Explorer C are presented. The amount of nitric oxide in the lower E region is shown to depend on latitude, longitude, and magnetic activity. Near the equator the density at the peak of the NO layer is typically about 2¿107 cm-3 and varies little with longitude or magnetic activity, except during major storms. At high latitude (up to 68¿ geographic latitude), peak densities are typically 2 or 3 times larger and much more variable. A longitudinal dependence is found in both geographic and geomagnetic coordinates, with minimum densities found near 45¿E geomagnetic longitude and maxima near 135¿W geomagnetic longitude. At 40mD dip latitude the half amplitude is about 30%.