Parent guides · 4 months
Your fifth month, day by day
Days 121 to 150: rocking toward rolling, toy hand-offs, babble, cause and effect, the sleep-training question, teeth maybe, and the safety sweep for a baby who grabs, with one new thing to try every day.
Every note draws on the 4-month guide and cites its sources. Babies don’t keep calendars: read each day as “around now”, and let your pediatrician’s read of your baby beat any note.
← Your fourth month, day by day (days 91 to 120)Your sixth month, day by day (days 151 to 180) →
Week 17: month five begins
Rocking toward rolling, hand-offs, babble, cause and effect, mirrors, and sleep at four months.
Day 121Month fiveA new month begins: what's coming by 6 months (laughs, raspberries, rolling), corrected age if your baby came early, and the warning signs that are still about you.Try: Toy circle tummy time
Day 122Rocking, kicking, swimmingThe tummy rocking and arm 'swimming' that lead to rolling, which way most babies roll first, and what a baby who rolls changes about where they sleep.Try: The swim-and-rock watch
Day 123Toy hand-offsFrom bringing things to the mouth to a raking grip, then hand to hand and the pincer: what the hands are working on, and why no special gear is needed.Try: Toy hand-offs
Day 124Babble beginsBabbling often starts around 4 months with the rise and fall of your own language. Copy the sound, then add a word, and count how many turns you can keep going.Try: Copy, then add a word
Day 125I can make things happenAround 4 months babies discover that a kick shakes the mat and a wave rattles the rattle. What that memory looks like in the lab, and a safe way to stage the concert.Try: The crib-kick concert
Day 126Eyes and spiralsAt 4 months babies see colors and shades better and may love circles and spirals, which is one reason faces win. Mirror time today, and the eye signs worth a call.Try: Mirror smiles
Day 127Eighteen weeks: sleep at 4 to 5 monthsEighteen weeks: how much sleep babies this age need, why 'sleeping through' varies so much from baby to baby, and the short bedtime routine with the best evidence behind it.Try: Brush, book, bed
Week 18: calm, teeth, and names
The sleep-training question, one step at a time, doubling, safe mouthing, teeth maybe, and the name game.
Day 128If you're thinking about sleep trainingOptional, and only if night waking is wearing you down: the basics first, gradual versus checking, what the trials found and at which ages, and the rules that never bend.Try: Drowsy, then down
Day 129Calm with lessThe AAP's ladder for a fed, changed, rested baby who's still fussy: your eyes, then your voice, then a hand on their chest, and only then picking up. Practice it by daylight.Try: One step at a time
Day 130DoublingMany babies double their birth weight at about 4 months. Milk is still the only food and drink, cereal in the bottle is a choking risk, and a bathroom scale makes a keepsake.Try: The weigh-in at home
Day 131Mouthing, made safeEverything goes in the mouth now, and that's learning. The small-parts test, why household things aren't tested, batteries and magnets, and a basket of safe things to gum.Try: A safe mouthing basket
Day 132Teeth, maybeTeething usually starts between 4 and 7 months, but drool alone doesn't prove a tooth is coming. What research found, what helps sore gums, and the products to skip.Try: The gum rub
Day 133The name gameYour baby knows the sound of their own name long before they turn to it. Why to say it often, what a lab study found at 4½ months, and a one-minute game.Try: The name game
Day 134Nineteen weeks: temperamentEasygoing, intense, or slow to warm up: your baby's style is showing. What calms each kind, the script for a visiting relative, and a slow-approach game to try.Try: The slow approach
Week 19: the floor and the table
Temperament, floor over containers, peekaboo, books, lap bounces, and why solids wait.
Day 135Floor time beats container timeWHO's numbers for this age: floor play several times a day, 30 minutes of tummy time, and no more than an hour at a time strapped in. Plus a one-day tally to see where you stand.Try: The container count
Day 136Peekaboo, month fiveSometime after 4 months, babies begin to learn that hidden things come back. Why the famous study is contested, why anticipation is the real game, and a cloth version to try.Try: Peekaboo with a cloth
Day 137Books, month fiveShared reading from birth is the AAP's advice, and a randomized trial found fewer behavior problems years later. How to read to a baby who eats the book, and a point-and-name game.Try: Point and name
Day 138Lap bounce songsFeet on your thighs, hands under the arms, and a rhyme with a pause before the big finish: leg strength, rhythm, and laughter in one song. Plus a word about your pelvic floor.Try: Lap bounce songs
Day 139Solids: not yetWatching you eat isn't a green light. CDC and WHO put first foods at about 6 months, what the readiness signs are, the iron and vitamin D questions, and a no-food high-chair rehearsal.Try: The high-chair rehearsal
Day 140Twenty weeks: safe sleep for a rollerRolling changes the rules: the swaddle ends at the first attempt, the back is still where every sleep starts, and a baby who rolls both ways can be left. Walk the crib tonight.Try: The bare-crib audit
Day 141Falls happen fast nowRolling can start the moment you look away, and babies this age don't fear edges. One hand on the baby on any raised surface, every time, and what to do if a fall already happened.Try: The one-hand rule
Week 20 and five months
A roller's safe sleep, falls, burns, the car seat, sun, fever, your turn, both of you, and five months.
Day 142Burns and hot drinksGrabbing hands reach mugs now. The two rules that prevent most scalds, no baby plus hot drink and a water heater at 120°F, and the counter habit that makes them automatic.Try: The far-side-of-the-counter habit
Day 143The car seat as they growRear-facing to the seat's limits, a convertible seat when the infant seat is outgrown, straps at or below the shoulders, chest clip at the armpits, and the pinch test that checks it all in a minute.Try: The pinch test
Day 144SunBabies under 6 months stay out of direct and indirect sun: shade, light long sleeves, a wide-brimmed hat, and no outings from 10 a.m. to 4 p.m. Why daylight still matters, and a shade walk to try.Try: The shade walk
Day 145Fever at 4 to 5 months100.4°F is a fever. At 3 to 6 months that means a call within 24 hours, sooner for 104°F or a baby who seems very sick. The thermometer rules, the medicine rules, and a practice run on a well day.Try: The temperature practice
Day 146Talk, pause, and copyServe and return at 5 months: copy the sound, add a word, say your turn, and wait. Why the pause is the whole trick, and a turn-counting game to see how long you can keep it going.Try: Your turn
Day 147Twenty-one weeks: both of youThe 4-month depression screen just happened. Partners get depressed too, and 3 to 6 months is the window one review flagged. The question to ask each other tonight, and the hotlines.Try: The partner's lap bounce
Day 148Family life is the curriculumNo lessons needed. Your baby learns from watching you cook, fold, and water plants while you say what you're doing. Why the chores count as talk time, and a laundry narration to try.Try: The laundry narration
Day 149What's nextWhat changed in 150 days, from two hours of crying to a baby who chuckles and grabs, and what the 6-month list and the 5-month guide hold next: rolling, sitting with support, first foods.Try: Five-month photo and letter
Day 150Five monthsFive months. The 6-month list as coming soon, for most: laughs, raspberries, rolling, straight arms. What you've done in 150 days of answering, a first-roll video to keep, and the next guide.Try: The first-roll video