Most US guidance puts a baby's room at 68–72°F (20–22°C). The UK's Lullaby Trust recommends a cooler 16–20°C, about 61–68°F. The American Academy of Pediatrics doesn't set a number at all. What every source agrees on is the part this guide is really about: avoid overheating, and keep the room steady through the night.
The number is the easy half. The hard half is holding it in a real Los Angeles room: an upstairs nursery under the roof, west-facing glass, a thermostat down the hall. That is what the rest of this page covers.
You'll see three different answers depending on where you look. They aren't really in conflict: they come from different bodies answering slightly different questions.
| Source | What it says | How to read it |
|---|---|---|
| American Academy of Pediatrics | No specific number. Avoid overheating; dress the baby in one more layer than you would wear; no hat indoors. | The AAP focuses on the baby's own signs. The room number is yours to set. |
| Common US guidance (pediatricians quoted in US parenting media) | 68–72°F (20–22°C) | The figure most American parents will hear. A sensible target for a lightly dressed baby. |
| The Lullaby Trust (UK) | 16–20°C (about 61–68°F), with light bedding or a well-fitting sleep bag | Cooler, and paired with how the baby is dressed. Useful on mild LA nights when the room naturally drops below 68. |
| U.S. EPA (humidity) | Below 60% relative humidity, ideally 30–50% | Not a temperature, but it decides whether 70°F feels comfortable or clammy. |
On overheating, the AAP is direct: "Overheating can increase the risk of SIDS." That's why every source leans cooler rather than warmer, and why the AAP points you to the baby's own signs rather than a single dial setting.
Setting the thermostat to 70 doesn't make the nursery 70. In the rooms we see, the gap usually comes from one of these:
| What's happening | Where we see it | What it does overnight |
|---|---|---|
| The upstairs room under the roof | 1950s–70s South Bay tract homes in Torrance and Redondo Beach; second-storey additions | Heat stored in the attic keeps the room warm long after sunset, while the downstairs thermostat is satisfied. |
| West- or south-facing glass | Westside bungalows, Playa Vista top floors | Late-afternoon sun loads the room right before bedtime. |
| The thermostat is somewhere else | Almost every single-zone home | The system responds to the hallway, not the crib. |
| An oversized AC | Window units and big wall units in small rooms | It cools fast, shuts off, and leaves moisture behind, so the room swings and feels damp. ENERGY STAR explains the cause. |
| Coast versus inland | Manhattan Beach and Santa Monica versus Culver City and Beverly Hills | Marine-layer nights run cool and humid; inland nights stay warmer. The hottest coastal stretch usually comes in September and October. |
If your nursery is the upstairs room that never cools, we wrote a whole post on it: why the upstairs nursery is so hot, and how to fix the one room.
Holding a temperature is a system problem, not a thermostat problem. In order:
Getting a nursery ready from scratch? Our nursery room-prep checklist covers temperature, humidity, sound and air in one list.
We don't set a number and walk away. We measure the room, find out why it drifts, and design it to hold.
The Free Air Check. We read temperature and humidity at crib height, compare them with the thermostat, and find what's driving the gap.
We size the room's climate control from a load calculation, place it so air never crosses the crib, and add filtration where the room needs it.
We re-measure the finished room against what we measured at the start and give you the before-and-after in writing.
Most US guidance puts a baby's room at 68 to 72°F (20 to 22°C). The UK's Lullaby Trust recommends 16 to 20°C (about 61 to 68°F). The American Academy of Pediatrics does not set a number; it advises against overheating and suggests dressing a baby in one more layer than an adult would wear in the same room.
74°F sits above the 68 to 72°F range most US guidance gives and well above the UK's 61 to 68°F. Rather than relying on a number alone, the AAP says to check the baby for sweating, a hot chest or flushed skin, and to remove a layer if you find them.
65°F is below most US guidance but inside the UK's recommended 16 to 20°C range. What matters more is how the baby is dressed: the AAP suggests one more layer than you would wear, and a wearable blanket rather than loose bedding.
The EPA recommends keeping indoor relative humidity below 60%, ideally between 30% and 50%. In Los Angeles a room can drift above that on marine-layer mornings near the coast and well below it during Santa Ana winds.
Yes, as long as the airflow is not pointed at the baby. The Lullaby Trust gives the same advice for fans. A right-sized inverter mini split can run quietly all night at low speed, which keeps the temperature steadier than a unit that switches on and off.
Usually not. A hallway thermostat reports the hallway. Put a room thermometer near the crib, out of direct sun, and check it at night as well as during the day; the Lullaby Trust also recommends using a room thermometer.
The Free Air Check measures temperature and humidity where your child sleeps and tells you plainly why the room drifts, and what would hold it steady.
Get Your Free Air CheckThis guide covers room comfort and climate. For questions about your baby's health or sleep safety, talk with your pediatrician.
