Sunrise & Sunset in London — Times for Any Date

Why London's daylight swings by nearly nine hours

London sits at about 51.5° north, and that single number explains almost everything about its sunrise and sunset. At this latitude the Sun's daily arc tilts steeply with the seasons, so the length of the day changes faster than it does for any city closer to the equator. At the June solstice the Sun is up for 16h 38m; at the December solstice, 7h 49m — a swing of 12h 17m between the two extremes of the year.

This page computes sunrise, sunset, solar noon and the golden and blue hours for any date you enter, from the Sun's position rather than from a printed table. That matters at a high latitude, where "London" time and "London" daylight are two different questions: the mathematics works for the exact coordinates you are standing on, not for a city-centre average.

The formula behind every London sunrise

Sunrise and sunset are not stored values — they fall out of the Sun's geometry for that day. The calculator implements the NOAA solar-position algorithm, and every figure on this page is produced by the four steps below.

1. Fractional year. The day of the year becomes an angle: γ = 2π / 365 × (dayOfYear − 1 + 0.5).

2. Equation of time. The gap between apparent and mean solar time, in minutes: eqTime = 229.18 × (0.000075 + 0.001868 cos γ − 0.032077 sin γ − 0.014615 cos 2γ − 0.040849 sin 2γ).

3. Solar declination. How far the Sun sits above or below the celestial equator: δ = 0.006918 − 0.399912 cos γ + 0.070257 sin γ − 0.006758 cos 2γ + 0.000907 sin 2γ − 0.002697 cos 3γ + 0.00148 sin 3γ.

4. Hour angle. The Sun's angular distance from local noon at the moment it crosses the horizon, solved at the standard zenith of 90.833° that folds in atmospheric refraction and the Sun's own radius: cos H = cos(90.833°) / (cos φ cos δ) − tan φ tan δ.

Solar noon then lands at 720 − 4 × longitude − eqTime + timezone × 60 minutes, and sunrise and sunset sit four minutes either side for every degree of hour angle: sunrise = noon − H × 4 and sunset = noon + H × 4. At London's longitude (−0.13°) that puts solar noon within a few minutes of 12:00 all year — 12:02 on the summer solstice and 11:59 on the winter solstice.

UTC or BST? The one adjustment to make

The calculator is fixed to London's standard offset of UTC±0, so every time it prints is in Coordinated Universal Time — the same clock as Greenwich Mean Time. That is exact for about five months of the year, and one hour early for the rest.

From 29 March to 25 October 2026 London runs British Summer Time, one hour ahead of UTC. Add an hour and the clock matches the wall: the 21 June sunset the calculator reports as 20:21 is 21:21 BST, and sunrise is 04:43 BST, not 03:43. The 20 March equinox sits before the change, so its figures are already on the clock; in winter the two clocks agree, so the 15:53 sunset on 21 December is the time you actually see.

Three worked examples

Each example below is the calculator's own output for the date, run through the algorithm above. Times are listed in UTC first, with the BST equivalent in brackets for the summer dates.

Example 1 — the summer solstice, 21 June 2026

• Solar noon: 12:02 UTC (13:02 BST)
• Sunrise: 03:43 UTC — 04:43 BST
• Sunset: 20:21 UTC — 21:21 BST
• Length of day: 16h 38m
• Evening golden hour: 19:27–20:50 UTC (20:27–21:50 BST), a 83-minute window
• Blue hour closes at 22:09 BST

This is the longest day of the year, and the latest sunset lands in the last week of June rather than on the solstice itself — because the equation of time drifts through the month, sunset on 30 June is still 20:21 UTC (21:21 BST) even though the day is already shortening.

Example 2 — the winter solstice, 21 December 2026

• Solar noon: 11:59 GMT
• Sunrise: 08:04 GMT
• Sunset: 15:53 GMT
• Length of day: 7h 49m — the shortest of the year
• Morning golden hour: 07:39–09:05 UTC, a 86-minute window
• Evening golden hour: 14:52–16:19 UTC

The whole usable day is squeezed into the six hours around noon. Because solar noon barely moves through the year, the winter loss happens at both ends: sunrise is roughly two hours later and sunset two and a half hours earlier than in June.

Example 3 — the March equinox, 20 March 2026

• Solar noon: 12:09 UTC
• Sunrise: 06:05 UTC
• Sunset: 18:13 UTC
• Length of day: 12h 08m

The equinox is the date the day and night are meant to balance, yet the calculator returns 12h 08m — a few minutes longer than twelve hours. That extra time is not an error: the standard zenith of 90.833° already counts atmospheric refraction (about 0.83°) and the Sun's radius, so "sunrise" is when the upper limb first appears, not the centre. At London's latitude the effect adds roughly 8 minutes to an equinox day.

Daylight through the year at 51.5° N

The table below is the calculator's output on eight dates spread across 2026. Read it as the shape of a London year: a steep climb from January to June, a broad plateau through July, and a mirror-image fall to December.

Two things stand out. First, the year is not symmetrical around the solstices in clock terms: the mornings gain their light fastest in the two months after the solstice, which is why a January morning feels brighter than a late-November one even though both are cold. Second, the March and September equinoxes both run slightly over twelve hours for the refraction reason above, so "equal day and night" on the clock arrives a couple of days before the astronomical equinox.

Golden hour and blue hour, the London way

The calculator defines the golden hour as the window in which the Sun stands between −4° and +6° above the horizon, and the blue hour as the band from −6° to −4° that opens and closes it. At London's latitude those windows are genuinely long. On 21 June the evening golden hour runs 19:27–20:50 UTC — 20:27–21:50 BST, a full 83 minutes — and the blue hour does not close until 22:09 BST.

Winter inverts the balance. On 21 December the morning golden window is 07:39–09:05 UTC, a 86-minute stretch, and the evening one is barely shorter. The Sun never gets high, so the light stays soft for hours — the opposite of the harsh midday you would get at the same clock time in a tropical city.

Where the numbers can surprise you

• The calculator prints UTC. Between 29 March and 25 October 2026, add one hour for British Summer Time before comparing it with a clock on the wall.
• Refraction is already included. The 90.833° zenith means "sunrise" is the first appearance of the upper limb, not the centre of the disc — which is why equinox days run slightly over twelve hours.
• A clear horizon sees more sun. The algorithm assumes an unobstructed sea-level horizon. A hill to the east can delay sunrise by tens of minutes in winter, and a sea view can bring it forward.
• Elevation helps a little. Standing a hundred metres higher rises above the horizon sooner, advancing sunrise by roughly a minute.
• Solar noon is not 12:00. It ranges from 11:59 to 12:09 UTC across the year, because longitude and the equation of time both push it around.

Sources and standards

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