In this study, the crosswind (wind component perpendicular to a path, <i>U</i><sub>⊥</sub>) is measured by a scintillometer and estimated with Doppler lidar above the urban environment of Helsinki, Finland, for 15 days. The scintillometer allows acquisition of a path-averaged value of <i>U</i><sub>⊥</sub> (<span style="border-top: 1px solid #000; color: #000;"><i>U</i><sub>⊥</sub></span>), while the lidar allows acquisition of path-resolved <i>U</i><sub>⊥</sub> (<i>U</i><sub>⊥</sub> (<i>x</i>), where <i>x</i> is the position along the path). The goal of this study is to evaluate the performance of scintillometer <span style="border-top: 1px solid #000; color: #000;"><i>U</i><sub>⊥</sub></span> estimates for conditions under which <i>U</i><sub>⊥</sub> (<i>x</i>) is variable. Two methods are applied to estimate <span style="border-top: 1px solid #000; color: #000;"><i>U</i><sub>⊥</sub></span> from the scintillometer signal: the cumulative-spectrum method (relies on scintillation spectra) and the look-up-table method (relies on time-lagged correlation functions). The values of <span style="border-top: 1px solid #000; color: #000;"><i>U</i><sub>⊥</sub></span> of both methods compare well with the lidar estimates, with root-mean-square deviations of 0.71 and 0.73 m s<sup>−1</sup>. This indicates that, given the data treatment applied in this study, both measurement technologies are able to obtain estimates of <span style="border-top: 1px solid #000; color: #000;"><i>U</i><sub>⊥</sub></span> in the complex urban environment. The detailed investigation of four cases indicates that the cumulative-spectrum method is less susceptible to a variable <i>U</i><sub>⊥</sub> (<i>x</i>) than the look-up-table method. However, the look-up-table method can be adjusted to improve its capabilities for estimating <span style="border-top: 1px solid #000; color: #000;"><i>U</i><sub>⊥</sub></span> under conditions under for which <i>U</i><sub>⊥</sub> (<i>x</i>) is variable.