For a north-facing room that's gloomy all winter, buy one large, bright light for the ceiling and run it cool in the morning and warmer through the afternoon. The room's problem is that it gets no direct sun for half the year, and lamps at eye level can't stand in for that however many you add. Sunday Light, the artificial skylight we make in London, puts 34,500 lumens into the room from the ceiling and changes colour with the time of day.
Why north-facing rooms are gloomy all winter
Between the September and March equinoxes, the sun rises south of due east and sets south of due west. A window facing due north gets no direct sun for that whole half of the year. What comes in is diffuse light from the northern sky, and it is bluish. A clear northern sky measures 15,000-27,000K on the colour temperature scale, against about 6,500K for an overcast one, which is why a north room can look tinged with blue.
And there isn't much daylight to go round. On 21 December, London has 7 hours 49 minutes between sunrise, just after 8am, and sunset, just before 4pm. At midday the sun is only 15 degrees above the horizon. Heathrow averages 55 hours of sunshine in December against 208 in June, on the Met Office's 1991-2020 figures. So a north room in December runs on its lamps for most of the waking day, at the 100-300 lux most homes manage. Outdoors is 50 to 100 times brighter than that.
Which colour temperature to use, and when
The usual decorating advice for north rooms is to counter the blue cast with warm colours, such as whites with a touch of yellow pigment, and warm bulbs do the same job after dark. In the morning, though, your body clock wants the opposite. Bright, cool light is the signal that the day has started, and warm, dim light belongs to the evening.
A good pattern for a north room is 5000-6000K and as bright as you can get it in the morning, warmer and dimmer through the afternoon, and 2700K or lower from early evening. Circadian researchers put numbers on this in a 2022 consensus paper (Brown et al., PLOS Biology). Through the day, at least 250 lux at eye level of melanopic light, which is light weighted for the clock-setting cells in the eye. In the three hours before bed, no more than 10. Most indoor bulbs reach those cells substantially less efficiently than daylight of the same brightness, so a room can look bright enough and still fall short.
What to buy, from the cheapest
An uplighter is the best cheap buy for a north room. It aims its light at the ceiling and turns the ceiling into a large, soft source. IKEA's ISJAKT is £79 for a dimmable 1,850-lumen uplighter with a 350-lumen reading light, and it works best under a white ceiling. It is 2700K warm white, so the room gets evening-coloured light all day.
A SAD lamp treats the winter low rather than the room. The NHS says to choose one that gives 10,000 lux, is UV-free and has a UKCA or CE mark. Lumie's Vitamin L (£99 list price in October 2026) gives 10,000 lux at 20 cm and 2,500 lux at 50 cm, for a session of about 30 minutes. It lights your face while you sit at it, and the room stays as dim as before. Our guide to light therapy for SAD covers the dose in detail.
Sky panels from Philips, Govee and Nanoleaf fix flat to the ceiling, look like a patch of sky and follow a daily schedule. At 1,400-7,000 lumens they make a good ceiling light, short of daylight. The four kinds of artificial skylight compares them with recessed systems and with Sunday.
Why the light should come from overhead
Daylight reaches a room from a large area of sky, so it lights the whole space without a glare point. A lamp is a small point at eye level. The brighter you make it, the harsher it is to look at, and its light still falls off with the square of the distance. A large, bright source overhead is the indoor substitute for sky, and in a north room in winter it is the only one available. The brightest light for a dark flat sets out why extra lamps don't close the gap.
Sunday is built that way. The LED sits at the bottom of the arm and shines up at a sheet 120 cm across. The sheet scatters the bluer light and reflects the warmer light, by Rayleigh scattering, as the atmosphere does. Look up and you see a blue sky glow with a warm, sun-like centre, and the room gets soft, indirect light. It gives 10,000 lux at 60 cm and has a CRI of 97+, so wood, skin and paint look the way they do outdoors.
Set a schedule once in the app and it follows the day for you: cool 6000K in the morning, then warmer and dimmer through the afternoon towards 2650K, and we recommend having it off by around 6pm. Water flows through the tubes in the arm to cool the LED, which is what lets it hold this brightness all day.
Will it fit in a UK flat?
Sunday hangs from a ceiling rose like a chandelier, and a qualified electrician fits it in 1-2 hours. Nothing is recessed, so the ceiling isn't cut and solid concrete is no obstacle. If the room has no ceiling light point, it can be powered by a cable run to a wall socket.
The ceiling needs to be 240 cm or higher. From 240 to 280 cm, a reduced-height mount holds the disc 11 cm below the ceiling; under about 260 cm, put it over a table or desk rather than a walkway. At full brightness it draws 400 W, about 10p an hour at UK rates.
Sunday Light, our indoor sunlight fixture, is £5,900 in the UK, $6,900 in the US and €6,900 in Europe, with free worldwide delivery, and it ships within 5 working days. We install it in London for £450, and you can see one by appointment in London, New York, Palo Alto and Zurich through our contact page. The full specification is on the sunlight ceiling light page.
