Colour maps showing the temperature distribution of our model atmospheres in a plane perpendicular to the terminator for three different transition angles between a 650 K dayside and a 300 K nightside (from left to right, the day–night transition angle is β = 15, 30, and 60°). The inner white circle represents the inner part of the planet with a radius assumed to be equal to that of GJ 1214 b (17.600 km). The star is on the left and the observer on the right on the y = 0 line. From the centre outward, the five solid lines are respectively the 10⁶, 10³, 1, 10⁻², and 10⁻⁴ Pa pressure levels. Below the 10³ Pa level, the atmosphere is assumed to efficiently redistribute heat and is horizontally isothermal. These maps are to scale and show that the dayside is noticeably more extended than the nightside.