Sun Height Calculator UK
Calculate the sun’s altitude angle for any UK date, time, and location, then visualise the full-day sun path instantly.
Tip: choose your city first, then refine coordinates if needed.
Expert Guide: How to Use a Sun Height Calculator in the UK
A sun height calculator helps you determine the angle of the sun above the horizon at a specific place and time. In technical terms, this is called solar altitude. In the UK, where latitude varies from roughly 50°N in the south to nearly 59°N in the north mainland and above 60°N in Shetland, solar altitude changes significantly through the year. This is why winter days can feel dim and low-light while summer days are bright and long.
If you are planning solar panels, setting up a garden, designing shading, shooting outdoor photos, planning drone work, or simply trying to understand daylight conditions, sun height is one of the most useful metrics you can calculate. The tool above gives you practical values quickly and visualises the full day path so you can make decisions with confidence.
What does “sun height” mean?
Sun height is the vertical angle between the horizon and the sun. If the sun is directly on the horizon, the altitude is 0°. If it is directly overhead, altitude is 90° (which never happens in the UK). Negative values mean the sun is below the horizon.
- 0° to 10°: very low sun, long shadows, golden-hour effects near sunrise or sunset.
- 10° to 35°: moderate sun height, common for many UK daytime periods outside midsummer.
- 35° to 62°: high sun for UK latitudes, more likely around midday in late spring and summer.
Why sun height matters in the UK
Because the UK is at relatively high northern latitudes, the yearly swing in solar altitude is large. In winter, the sun remains low all day, reducing irradiance and increasing shadow length. In summer, noon altitude rises substantially, improving solar gain and brightness. This seasonal variation affects energy planning, architecture, transport safety, and outdoor comfort.
- Solar PV performance: panel tilt and expected output vary with sun angle and season.
- Building design: facades and glazing need shading strategies tuned to high summer sun and low winter sun.
- Photography and film: shadow length and direction depend directly on altitude and azimuth.
- Agriculture and horticulture: light intensity and daylength influence crop and greenhouse management.
- Road safety: low-angle sunlight can increase glare risk during commuting hours.
UK Solar Altitude Benchmarks by City
The table below gives representative solar noon altitude values for major UK cities. These are based on standard astronomical approximations and show the strong north-south contrast across the country.
| City | Latitude | Noon Altitude (June Solstice) | Noon Altitude (Equinox) | Noon Altitude (December Solstice) |
|---|---|---|---|---|
| London | 51.5°N | 61.9° | 38.5° | 15.1° |
| Manchester | 53.5°N | 59.9° | 36.5° | 13.1° |
| Birmingham | 52.5°N | 60.9° | 37.5° | 14.1° |
| Edinburgh | 56.0°N | 57.4° | 34.0° | 10.6° |
| Aberdeen | 57.1°N | 56.3° | 32.9° | 9.5° |
Notice how December noon altitude can be close to 10° in northern Scotland. That is why winter shadows are extremely long and direct sun exposure windows are narrow.
Daylength Differences Across the UK
Sun height and daylength are related but not identical. Daylength describes how long the sun is above the horizon; altitude describes how high it gets. You need both when planning outdoor work or solar systems.
| Location | Approx Daylength in June | Approx Daylength in December | Seasonal Difference |
|---|---|---|---|
| London | 16h 38m | 7h 50m | 8h 48m |
| Manchester | 16h 47m | 7h 37m | 9h 10m |
| Edinburgh | 17h 36m | 6h 57m | 10h 39m |
| Aberdeen | 17h 44m | 6h 50m | 10h 54m |
How to interpret these numbers in real projects
If you are sizing a rooftop PV system in Aberdeen, summer performance windows are generous, but winter generation can be constrained by both low altitude and short daylength. In London, there is still major seasonality, but winter noon altitude and daylength are modestly better. For architecture, the lower winter sun can be valuable for passive heating if glazing and shading are designed properly.
How this UK Sun Height Calculator works
The calculator uses a standard solar position model with date, time, latitude, and longitude. It estimates solar declination and equation of time, then calculates hour angle and altitude. For practical UK work, this is sufficiently accurate for planning, layout, and educational use. The chart then plots altitude throughout the selected date so you can see when the sun rises, peaks, and sets.
- Geometric altitude: purely geometric position of the sun.
- Apparent altitude: includes atmospheric refraction, mostly relevant when the sun is low.
- Azimuth: compass direction of the sun, useful for orientation and shadow prediction.
Step-by-step usage tips
- Select a UK city or choose custom coordinates.
- Enter date and local UK time.
- Choose geometric or apparent altitude.
- Click Calculate to view altitude, azimuth, daylight estimate, and chart.
- Check the chart for best solar window and low-angle glare periods.
Best practices for professionals
For solar installers
Use sun height with roof pitch and azimuth to estimate seasonal mismatch between panel orientation and sun path. Low winter altitude increases the importance of avoiding nearby obstructions. Even small trees or chimneys can remove a significant part of useful winter sun.
For architects and designers
Combine summer noon altitude with facade geometry to design overhangs that block high sun while allowing low winter sun penetration. Validate with both equinox and solstice conditions to avoid over-shading or overheating.
For photographers and media teams
Plan shots by targeting altitude ranges rather than just clock time. In UK winter, usable soft light can extend longer because the sun remains low. In summer, the high midday sun may be harsh, so early and late windows are often preferred.
Common mistakes to avoid
- Ignoring latitude differences: London and Aberdeen can have very different solar conditions.
- Confusing local clock noon with solar noon: the sun often peaks before or after 12:00.
- Skipping longitude: east-west position shifts solar timing by minutes that matter in precise work.
- Not checking winter angles: projects that look fine in summer may underperform in winter.
- Forgetting refraction near horizon: apparent sunrise and sunset can differ from geometric values.
Authoritative UK and Government Data Sources
For validation and deeper technical references, use authoritative public sources:
- UK Met Office (metoffice.gov.uk) for climate context, daylight seasonality, and weather interpretation.
- NOAA Solar Calculator (noaa.gov) for reference solar geometry methods.
- UK Hydrographic Office (gov.uk) for official astronomical and navigational publications.
Final takeaway
A high-quality sun height calculator is one of the simplest tools that can dramatically improve planning decisions in the UK. Whether your goal is better PV yield, safer road lighting analysis, improved building comfort, or better visual content scheduling, accurate sun altitude and daily path data give you objective evidence instead of guesswork. Use the calculator above for instant results, compare dates across seasons, and always evaluate your project under both summer and winter conditions.