Sunlight through the year
How much sun does your roof get?
The answer changes every month. In June, a well-placed south-facing roof can catch five or more hours of useful sun a day. In December, the same roof might manage barely one. That gap is why orientation matters, why shading matters more in winter, and why two identical-looking houses on opposite sides of a street can have very different solar potential.
Below you can see what that seasonal shift looks like on an example roof — then check your own.
Check your roof
A Solarable Report shows your likely roof direction, a Solarable Score, and listed installers covering your postcode.
See it on an example roof
A year of sun on one roof.
Press play — or drag the scrubber — to step through January to December. The colours use one shared scale across all twelve months, so December's blue really does mean far less sun than June's red.
Sunlight through the year
The seasons
Why a roof's sun changes so much through the year.
The UK sits between roughly 50° and 60° north, so the sun traces a very different arc depending on the season. In June it rises early, climbs high, and sets late — a south-facing roof is bathed in sun for most of the day. In December the sun stays low, rises late, and sets before 4pm, so the same roof receives a fraction of that energy. Not because the sun is weaker per hour, but because it shines for far fewer of them.
This is geometry, not guesswork, and it is predictable. The pattern in the replay above combines measured solar irradiance from the European Commission's PVGIS dataset with building-level solar data from Google. A well-sized system does meaningful work every month — just more of it from May to August, and less from November to January.
Direction
Why roof direction matters more than you might expect.
Not all of a roof sees the same sun. A roof that slopes south catches the sun at its highest arc. A roof that slopes north mostly catches reflected and diffuse light — useful, but far less of it.
The spectrum between is not uniform. South-east and south-west roofs lose only a little compared to due south (roughly 5–15%, depending on latitude and pitch). East and west roofs are more noticeably reduced, but can still support a useful installation — especially with a battery that holds morning or afternoon generation for the evening. In the shoulder months, when the sun's arc flattens, the gap between orientations is at its sharpest — which is why the warm zone in the replay shifts and narrows toward winter.
Shading
Why shading matters more in winter.
In summer, a chimney or a neighbouring tree casts a short, narrow shadow — the sun is high and the shadow stays small. In winter, that same chimney casts a long shadow that can sweep across a large section of roof from mid-morning on. With the sun as low as 15° at solar noon in December, even a modest obstacle can block a disproportionate share of the limited winter sun.
Modern inverter technology reduces, but does not eliminate, the penalty from partial shading. The example above is an unshaded roof; your own may have more or fewer obstacles — which is exactly why the roof check runs on your actual property, and why a qualified installer assesses shading in person before recommending a layout.
Reading the replay
What the colours mean.
The scale runs from deep blue (lower sun) to deep red (higher sun), and it is a shared scale across all twelve months — the same colour means the same relative intensity whether you are looking at February or July. That is what lets you compare months honestly: when December is almost all blue and June is mostly red, that is a real difference in how much sun reaches the roof, not a rescaling trick.
| What the colours show | What they don't |
|---|---|
| Where on the roof catches more or less sun each month | Exact kWh output from any part of the roof |
| How the pattern shifts between summer and winter | Whether the roof is economically viable |
| Which slopes and ridges catch the best angles | Per-panel production — resolution is at raster-cell level |
The replay is a relative spatial pattern, not a production forecast. Final suitability — pitch, shading, structural load, and system sizing — should be confirmed by a qualified installer in person.
Source: Includes solar data from Google. Monthly solar irradiance: © European Union, PVGIS v5.2, EU Science Hub.
See how this looks on your own roof.
Enter your address and we'll estimate your roof direction, show your home on a map, and generate a Solarable Report — including the sunlight-through-the-year view where data is available. No quote resale; you decide who to contact.
Check my roof →Common questions
FAQs.
Do solar panels work in winter in the UK?
Yes, though they produce less. A typical UK solar installation generates roughly 60–75% of its annual electricity between April and September, with the rest spread across the winter months. The panels do not stop working in winter — they respond to daylight rather than direct heat, so they still generate on clear and even overcast days. The exact split depends on your roof direction, any shading, and your location. An installer can model a monthly estimate for your specific roof.
Does a north-facing roof get enough sun for solar panels?
A purely north-facing roof is the least favourable orientation for solar in the UK, and most installers would not recommend it as the main surface. But many homes have two main roof faces — if the north slope is the front, the south-facing back is the surface that matters. Check your whole-roof picture with the roof check, and let an installer assess whether the south-facing area is sufficient.
How much sun does a roof need to make solar worth it?
There is no single threshold — it depends on system size, your electricity use, local shading, whether you add a battery, and the current tariffs. As a rough guide, a south or south-west facing roof with minimal shading is generally a strong candidate, and east or west roofs are often still viable. The Solarable Report gives an initial suitability band; a qualified installer can then model expected output and payback, and that survey is free from most listed installers.
Why does the sunlight pattern on the example roof change shape between months?
It is the geometry of the sun's path. In summer the sun rises far to the north-east, climbs high to the south, and sets to the north-west, spreading light across south-facing surfaces. In winter it rises south-east, stays low (around 15° at solar noon in southern England), and sets south-west — so only surfaces aligned with that low angle catch strong direct sun. Shadows are longer and the useful window is shorter, so the colour pattern shifts.
Is the sunlight-through-the-year view available for every UK roof?
It uses building-level solar data from Google and is available for most urban and suburban UK roofs, with strong coverage across the South West and major cities. Some rural areas and isolated properties fall outside the dataset — in those cases the Solarable Report shows an annual sunlight view instead, and a regional monthly chart is always available. Check your own roof to see which view applies.
Can I share or save the sunlight view for my roof?
The personalised replay on your Solarable Report is generated when you run the check and shown to you directly — it is not a saved permalink. We do not store or publish per-address roof imagery. To share findings with a family member or installer, you can run the check again at any time; the data refreshes from source.
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