Ive a leopard gecko and live in a generally cold flat.
The cold end , which has been around 21.5 has dropped to around 68.5F or 20.3C today (and can drop a bit lower at night). Is the too cold or should i think about a heat mat for this side to raise it slightly and maintain it higher.
room temps fine anything from 18/19c-24c is sufficient. As long as you have a heatmat controlled by a thermostat up the warm end your leo should be fine.
dont forget in the wild there is a night time drop so that is expected in the cool end any way.