What is a Street Alignment?

What is a Street Alignment?

A street alignment occurs when the rising or setting sun aligns precisely with the orientation of a street grid. During these moments, sunlight travels unobstructed down the length of the street, illuminating both sides of the road and creating dramatic long shadows. Buildings become silhouettes against a blazing sky, and the entire scene takes on an almost otherworldly glow.

The concept gained popular attention through "Manhattanhenge" - a term coined by astrophysicist Neil deGrasse Tyson to describe the phenomenon in New York City, where the setting sun aligns with Manhattan's east-west streets twice a year. The name draws a deliberate parallel to Stonehenge, the ancient monument designed to align with the sun during solstices.

But you don't need to travel to New York or Wiltshire to experience this magic. From Chicago's perfectly cardinal grid and Barcelona's rigorous Eixample, to Melbourne's Hoddle Grid and the Haussmann boulevards of Paris, cities all over the world offer their own versions of the phenomenon — and many of them produce alignments more often, and in better conditions, than Manhattan does.

The Science Behind It

The science is beautifully simple. Earth orbits the sun on a tilted axis - about 23.5 degrees from vertical. This tilt is what gives us seasons, but it also means the sun rises and sets at different positions along the horizon throughout the year.

The sun rises in the east and arcs across the sky before setting in the west — north of the equator the arc passes through the southern sky, south of the equator through the northern sky. As the seasons change, the sun's rise and set points slide along the horizon, returning to due east and due west only during the equinoxes in March and September.

Streets aren't laid out randomly. City planners typically orient grids along cardinal directions or at specific angles for practical reasons: maximising sunlight in winter, catching cooling breezes, or following the natural geography. When the sun's position on the horizon matches the bearing of a street, you get an alignment.

Here's the key insight: every street with a clear sightline to the horizon has specific dates when the sun aligns with it. A street running east-west will align during the equinoxes. A street angled slightly northeast will align on different dates - perhaps in April and August. Streets facing more northerly directions might only align in deep winter, while southerly-angled streets align in summer.

This means that, unlike Manhattanhenge's two specific dates, most cities experience alignments throughout the entire year on different streets. There's almost always one happening somewhere.

Why some cities are better for alignments than others

Three things make a city a great alignment city: geometric streets, accommodating latitude, and reliably clear horizons. Almost every CityHenge city sits in a sweet spot on at least two of those three.

The first is grid design. Chicago's near-perfect cardinal grid produces what locals call Chicagohenge twice a year, when the equinox sun sits squarely down every east-west street. Barcelona's Eixample, planned by Ildefons Cerdà in the 1850s, is so geometrically rigorous that its alignment dates are almost identical city-wide. Melbourne's Hoddle Grid from 1837, Adelaide's Light Plan, and Penn's 1682 plan for Philadelphia all do something similar: deliberate geometry that pays off centuries later in dramatic sun corridors.

The second is latitude. Mid-latitude cities — say, between roughly 25° and 55° — experience a wide range of sun positions throughout the year, so many different street bearings get their moment. Tropical cities like Darwin or Cairns have the sun overhead more of the time and fewer dramatic horizon angles; very high-latitude cities have the opposite problem in winter, when the sun barely climbs above the buildings. The supported set is mostly mid-latitude on purpose.

The third is the horizon itself. Perth and Los Angeles have west-facing streets that run straight to the ocean. Madrid averages over 2,500 hours of sunshine a year. Cities with low-rise outskirts and clean horizons — much of Australia, the US Sun Belt, southern Europe — produce gentler, longer alignment windows than dense vertical cities like New York, where the sun only finds the gap for a few minutes.

That's not to say tall, dense cities aren't worth chasing. Manhattanhenge is famous precisely because of how rare and brief it is, and because of how dramatic the canyon framing becomes when the sun finally drops into it. CityHenge tracks the easy cities and the hard ones — the question is just where on the spectrum your city sits.

When Do They Happen?

Street alignments are most spectacular around the equinoxes in late March and late September, when the sun rises and sets closest to due east and west. During these periods, any street oriented along an east-west axis will experience alignments.

But alignments happen year-round. The key is knowing the bearing of your street and matching it to the sun's position on the horizon.

The mechanics flip across the hemispheres. In southern-hemisphere summer the sun moves further south, so streets angled slightly southeast to southwest align — and the opposite in winter, with northerly streets getting their moment. North of the equator it's the mirror: northerly streets align in summer, southerly ones in winter. Mid-latitude cities in either hemisphere typically experience alignment conditions for most of their streets at some point during the year.

The exact date and time vary not just by street orientation but by your geographic location. A street in Perth aligns on different dates than an identically-oriented street in Sydney, simply because of their different longitudes and latitudes. The same street bearing in Madrid versus Berlin gives wildly different alignment dates — same physics, different latitude. This complexity is precisely why tools like CityHenge exist: calculating these alignments manually would require spherical trigonometry and astronomical tables.

Sunrise vs Sunset Alignments

Both sunrise and sunset create stunning alignments, but they have different characters.

Sunrise alignments mean early starts - often before 6am in summer - but reward you with quieter streets, cooler temperatures, and a sense of solitude. The light tends to be cleaner and sharper, without the haze that can build up during the day. East-facing streets obviously get sunrise alignments.

Sunset alignments are more accessible for most people's schedules and often benefit from atmospheric haze that softens and warms the light even further. Streets facing west get sunset alignments. City centres often buzz with activity during evening alignments, adding human elements - commuters, cyclists, couples - to your compositions.

Some photographers prefer one over the other, but the best approach is to appreciate both for their unique qualities.

How to Experience One

Witnessing your first street alignment doesn't require expensive equipment or expert knowledge - just some basic preparation.

Start by finding out when an alignment will occur on a street near you. CityHenge lists 55 cities across 17 countries, all with live sun and moon alignment data.

Arrive at your chosen location at least 20 minutes before the predicted alignment time. This gives you time to find a good vantage point, adjust your position, and simply soak in the building anticipation.

Safety matters. You'll be looking toward the sun on a street likely filled with traffic. Find a position on a footpath, in a median strip, or on elevated ground where you can watch safely. Never stand in traffic lanes, and be aware of vehicles around you.

Bring sunglasses for comfort during the lead-up, but know that the sun will be much easier to look at during the actual alignment when it's sitting on the horizon. The atmosphere filters much of the harsh light when the sun is this low.

If you're photographing, a smartphone is perfectly adequate - modern phones handle challenging lighting surprisingly well. For more control, a camera with manual settings lets you capture everything from the blazing sun to the shadowed street in a single frame.

Most importantly, take a moment to simply watch. The alignment itself lasts only ten to fifteen minutes - less if buildings block your sightline - and it passes quickly. Don't spend the entire time looking through a viewfinder. Experience it directly at least once.

Discover Your City's Alignments

Every supported city has its alignment moments waiting to be discovered. Melbourne's Collins Street glowing amber on an autumn evening. Manhattan's cross streets turning into corridors of fire on the famous Manhattanhenge dates. Chicago's Loop canyons catching the equinox sun. Paris's Haussmann boulevards lining up with the setting sun on dates Baron Haussmann himself probably never thought about.

CityHenge maps these moments across live major capitals and regional centres, then registers new cities as their first alignment datasets are built. Whether you're a photographer chasing perfect light, an urban explorer seeking new perspectives on familiar streets, or simply someone who appreciates those rare moments when a city reveals its hidden beauty, street alignments offer something genuinely magical.

All you need to do is look up, pay attention, and be in the right place at the right time.