The first cold snap of the season always seems to arrive overnight. You put your baby down in a room that felt perfectly comfortable at 7 p.m., and by 2 a.m. the house has dropped six degrees, and the furnace is running for the first time since March. Fall is the hardest season to get a nursery right, because the room you set up in the afternoon isn't the room your baby actually sleeps in. The good news is that the target is narrower and simpler than most new parents expect: a nursery should sit between 68°F and 72°F (20°C to 22°C), and that range doesn't change from summer to fall. What changes is how much work it takes to hold it there.
Why 68–72°F Is the Range
The American Academy of Pediatrics doesn't publish a specific thermostat number, but it clearly warns against overheating, which is associated with an increased risk of SIDS. The AAP's practical guidance is to keep the room at a temperature that's comfortable for a lightly clothed adult. In most homes, that lands squarely in the 68–72°F window, which is why nearly every pediatric sleep resource cites it.
Err toward the cooler end of that range rather than the warmer end. A slightly cool room is far easier to correct with an extra layer than a warm room is to correct once your baby is already sleeping. Babies also regulate their own temperature poorly for the first several months—they have a high surface-area-to-weight ratio and limited ability to shed heat—so the room does most of the work for them.
What Makes Fall Different
Three things make autumn nurseries harder to manage than summer or winter ones.
The first is the daily swing. A 75°F afternoon can become a 48°F night, and a nursery with western exposure will bank heat all day and then dump it after sunset. The second is your heating system's first run of the season, which tends to overshoot badly — forced-air heat can push a small room several degrees past the thermostat setting before it cycles off. The third is dry air. Running heat drops indoor humidity fast, and dry air makes a room feel cooler than the thermometer says while also irritating tiny nasal passages.
Put a separate thermometer in the nursery rather than trusting the hallway thermostat. Bedrooms routinely run three to five degrees off the reading in the main living area, and that gap is exactly the size of the mistake you're trying to avoid.
How to Dress Your Baby for the Room
Layering matters more than the thermostat number, and TOG ratings make it straightforward. TOG measures thermal insulation — the higher the number, the warmer the garment.
| Room temperature | Recommended TOG |
| 75°F+ (24°C+) | 0.5 TOG |
| 69–74°F (21–23°C) | 1.0 TOG |
| 61–68°F (16–20°C) | 2.5 TOG |
| Below 61°F (16°C) | 3.5 TOG |
For a nursery held at 68–72°F, a 1.0 TOG sleep sack over a footed cotton sleeper is the standard fall setup. Underneath, breathable natural fibers do the real work — these cute pajamas from Pi Baby are the kind of lightweight cotton base layer that lets heat escape instead of trapping it, which is the whole point of a base layer.
The general rule: dress your baby in one more layer than you'd wear to sleep comfortably in the same room. Not two. Overbundling is more common than underdressing, especially in fall when parents overcorrect after the first cold night.
Checking If Your Baby Is Too Warm
Hands and feet are unreliable — they run cool on almost every baby, at almost every temperature. Instead, slide two fingers against the back of your baby's neck or the center of their chest. Warm and dry is right. Damp, sweaty, or hot means overheated. Other signs include flushed cheeks, rapid breathing, and hair damp at the hairline.
If your baby is too warm, remove a layer rather than adjusting the thermostat midnight. It's faster, and it won't affect the rest of the house.
The Crib Itself
A safe sleep surface is a bare one: a firm, flat mattress with a single fitted sheet, and nothing else. No blankets, bumpers, pillows, or loose fabric, regardless of how cold the room gets. Warmth comes from what your baby wears, never from what's in the crib with them.
Sheet fabric does affect comfort more than people assume. Breathable cotton or muslin moves moisture away from the skin, while synthetic blends tend to hold heat. Crane Baby baby crib sheets are a solid choice here for exactly that reason — the fabric breathes rather than insulating.
Humidity and Drafts
Aim for 30–50% relative humidity. A cool-mist humidifier placed well away from the crib will offset the dryness that comes with running heat. Check for drafts at window frames and along exterior walls, and move the crib away from both — a crib positioned under a leaky fall window can sit several degrees colder than the rest of the room.
Frequently Asked Questions
Is 65°F too cold for a nursery? It's below the recommended range but manageable with a 2.5 TOG sleep sack. Sustained temperatures below 61°F warrant fixing the room itself.
Should I use a space heater? Avoid them in nurseries. If you must, keep it far from the crib, never leave it running unattended, and choose a model with tip-over shutoff.
Do babies need warmer rooms than adults? No. The same 68–72°F range applies. Babies need more layers, not a warmer room.