Satellite measurements of tropospheric trace gases are often only used when there are few clouds, which screens out 20 – 70 % of the data, depending on geographic region. While the lack of high-quality column measurements during cloudy conditions precludes validation of the satellite data, <em>in situ</em> surface measurements and model simulations can provide insight on the quantitative understanding of NO<sub>2</sub> during cloudy conditions. Here, we intercompare surface observations, satellite measurements, and models during 2019 over the contiguous U.S. to quantify how NO<sub>2</sub> concentrations are different under clear and cloudy skies. We find that <em>in situ</em> surface NO<sub>2</sub> measurements are, on average, +17 % larger on all days compared to restricting to clear sky days and +36 % larger during cloudy days versus clear sky days, with a wide distribution based on geographic region and roadway proximity: largest in the Northeast U.S. and smallest in the Southwest U.S. and near major roadways. WRF-Chem simulated surface NO<sub>2</sub> between cloudy and clear conditions is on average much larger than the observed differences: +59 % on cloudy days vs. clear days for the model. This suggests that NO<sub>2</sub> in WRF-Chem is more responsive to sunlight and associated photochemistry than in reality. Finally, using <em>in situ</em> NO<sub>2</sub> matched to provisional TEMPO data, we find the NO<sub>2</sub> differences between cloudy and clear conditions to be larger in the afternoon than morning. This study quantifies some of the biases in satellite measurements introduced by using only clear-sky data, and introduces some corrections to account for these biases.