Temperature: comfortable room warmth, nothing fierce
Mourning geckos are small rainforest geckos, and their temperature needs are closer to the room you live in than to a desert lizard's setup. Aim for the low seventies Fahrenheit at the cool end rising to the low eighties at the warmest point, which in most homes means no dedicated heater at all for much of the year. What they cannot tolerate is heat: sustained temperatures in the high eighties and beyond stress and can kill these little geckos, so an enclosure on a sunlit windowsill or beside a radiator is a real hazard. A small heat mat on a thermostat, on one side of the glass, covers cold houses and winter nights without cooking the whole tank.
Humidity: high, but cycling rather than constant
Humidity matters more than heat for this species. Keep the enclosure between roughly 60 and 80 percent, achieved by misting rather than by sealing the tank up tight. A thorough spray in the evening, when the geckos become active, lifts humidity toward the top of the range and leaves droplets for them to drink from leaves and glass. Through the following day it should drift partway down before you mist again. That daily rise and fall is healthier than a permanently fogged box, which grows mould and stale air. Good ventilation in the lid is part of the humidity system, not a leak in it.
Reading the geckos as well as the gauges
A cheap digital hygrometer and thermometer at mid-height in the enclosure give you numbers, but the geckos audit the setup themselves. Mourning geckos at the right humidity shed cleanly, stay plump and vocal, chirping and clicking at each other in the evening. Stuck shed clinging to toes and tail tips points to air that is too dry, while geckos that stay hidden and silent through the evening may be too cold. Because these geckos are so small, problems develop quietly, and the daily glance matters as much as the weekly gauge check. Eggs, which females lay glued in hidden corners, also hatch best in the same humid warmth, so stable conditions pay off twice.
The daily care rhythm that holds the ranges
Build the routine around the misting. Evening is the anchor: spray the foliage and glass, check the water in any shallow dish, confirm the gauges read in range, and glance at the geckos as they emerge. Morning needs only a light top-up mist in dry centrally heated homes, and nothing at all in humid ones. Wipe condensation patterns into your judgement: glass that clears fully by midday suggests the cycle is running dry, while walls still streaming at dusk suggest you can ease off. Small, steady corrections beat dramatic ones, because a mourning gecko colony experiences every swing multiplied across a dozen tiny bodies.
When the numbers will not settle
If humidity crashes daily despite misting, look at substrate and ventilation before buying gadgets: a soil-based or moss-retaining substrate holds moisture far better than paper, and a partially covered screen top slows the loss. If the room itself runs hot in summer, move the enclosure to the coolest wall rather than adding equipment that fights the whole room. Getting these basics recorded as the pet's routine, with misting and gauge checks ticked off as Care Teams tasks in KinsLe, means a gecko sitter or family member keeps the same cycle running in the same ranges while you are away.