Atmospheric water vapor effects represent one of the major limitations of repeat‐pass InSAR, and limit the accuracy of deformation rates derived from InSAR. The use of contemporaneous MERIS data to correct ENVISAT ASAR measurements shows a significant reduction in water vapor effects. After correction, the RMS differences between GPS and InSAR range changes in the satellite line of sight direction decreased to 0.55 cm with a reduction of up to 0.35 cm. It is also shown that it is possible to implement an extra ‘conservative’ cloud mask and obtain better water vapor corrections than that from using the official ESA cloud mask product.