The large-scale gradient in the bulk velocity of the solar wind, previously inferred from a study of large numbers of solar wind measurements made at two widely separated locations by Mariner 5 and the near-earth Explorers 33, 34, and 35 during mid-1967, is interpreted to be a heliographic latitude gradient. Nearly 2000 differences in hourly averages of the solar wind velocity observed at the two locations, after being corrected for differences in solar longitude, are analyzed by using a technique previously applied to the propagation of sector boundaries between Mariner 5 and earth. The higher velocities at the higher-latitude Explorers, as compared with those observed at the lower-latitude Mariner 5, imply a latitude gradient of roughly 15 km/s/deg. This value for the gradient is in excellent agreement with that obtained previously from the study of sector boundaries. A simple model of the velocity-latitude dependence is developed to illustrate that the observed relationship between the velocities at Mariner and the Explorers, (VM-275) =11+0.76(VE -275), is consistent with this gradient and with the latitude separation of the spacecraft. Further evidence of a latitude gradient is obtained by analyzing separately the velocities at the Explorers and at Mariner 5 as functions of latitude. This technique yields essentially the same relation between velocity and latitude as the multispacecraft analysis. The Vela 2, 3, and 4 solar rotation velocity averages observed near earth from 1964 through 1967 (interpreted by Hundhausen et al. (1971) as being due to a latitude gradient) are combined with solar rotation averages of the Mariner and Explorer data and then analyzed as a function of latitude to obtain a long-term value for the gradient. These single-location analyses consistently yield latitude gradients in the northern hemisphere below 71/4¿ that range between 10 and 15 km/s/deg. Interplanetary scintillation estimates of the solar wind velocity, obtained in 1972 and 1973, are also analyzed and yield a somewhat smaller latitude gradient of 4--6 km/s/deg. The latter values provide evidence of the existence of the gradient at higher heliographic latitudes.