In this work, we study seismic precursors from air temperature data of the National Center for Environmental Prediction (NCEP), Global Navigation Satellite System (GNSS) based Total Electron Content (TEC) and electron density retrieved from Swarm satellite (Alpha) data in Mw>=7.0 earthquakes in Mexico. The spatial-temporal evolution of seismic thermal anomalies is explored through NCEP, and synergistic observations of Swarm satellite and GNSS station are capable of providing more comprehensive information about disturbances in ionosphere. Our study may help explain the lithosphere-atmosphere-ionosphere coupling before earthquakes.