Chicagohenge 2026 and Manhattanhenge 2027 dates

Twice a year, in a city built on a grid, the setting Sun drops into the slot of a street and lights it end to end. New York calls it Manhattanhenge. Chicago calls it Chicagohenge. Toronto, Baltimore and Montreal each have their own. The name is borrowed from Stonehenge, and the mechanism is the same one: a fixed line on the ground, and a Sun whose setting point slides along the horizon through the year until the two agree.

The dates are not folklore. They fall out of two numbers — the bearing of your street, and the latitude you stand at — and you can compute them for any street in the world.

The next dates

Computed for a Sun sitting within two degrees of a flat horizon, which is the band where the alignment actually reads as an alignment.

City	Bearing	Window	Sun lowest on the line	Local time
Chicago	270° (due west)	19–23 September 2026	around the equinox	18:39–18:44
Chicago	270° (due west)	19–23 March 2027	around the equinox	18:39–18:44
Manhattan	299° (west-northwest)	25 May – 8 June 2027	28 May 2027	20:12
Manhattan	299° (west-northwest)	3–17 July 2027	14 July 2027	20:21

Two things in that table are worth more than the dates themselves. Chicago gets one window in autumn and one in spring, both on the equinox. Manhattan gets two windows that straddle midsummer instead. That difference is not a quirk of the calculation — it is the whole geometry, and once you see it you can predict your own city before computing anything.

Why Chicago lands on the equinox and Manhattan does not

Through the year, the point on the horizon where the Sun sets slides back and forth. At the equinoxes it sets due west — everywhere on Earth, at every latitude, which is what makes the equinox the equinox. From there it walks north until the June solstice, stops, and walks back south until December.

How far north it gets depends on your latitude. At Chicago's 41.9°N the setting Sun reaches roughly 302° at midsummer; at the equator it would barely leave 270°; in Reykjavík it swings much further. So each latitude has its own arc, and every bearing inside that arc is crossed exactly twice a year — once on the way up, once on the way back.

Chicago's street grid was laid out on the Public Land Survey System, whose lines run true north–south and east–west. Its major streets therefore point at 270°, the one bearing the Sun visits on the equinoxes. Chicagohenge is an equinox event by construction, and the same is true of every city surveyed on the same national grid.

Manhattan is the interesting case. The Commissioners' Plan of 1811 rotated the island's grid about 29° away from true north, to sit square with the shoreline rather than with the pole. The cross-streets consequently point at 299° instead of 270° — near the far end of the Sun's northern swing at that latitude. A bearing near the end of the arc is reached late on the way up and early on the way back, so the two crossings do not spread across the year: they close in around the June solstice, one in late May and one in mid-July. Push the bearing a few degrees further north and the two windows would merge into one at midsummer, then vanish entirely.

This is why the answer comes back as a range rather than a single day. Near the horizon the Sun's setting point moves slowly, a fraction of a degree per day, so an alignment does not switch on and off — it holds for several days, peaks, and fades.

Finding the dates for your own street

You need one number: the bearing of the street, measured clockwise from true north — 0° north, 90° east, 180° south, 270° west. Read it off any map along the axis you want the Sun to sit in. If you are aiming at a sunset, use the westward direction of the street; for a sunrise, the eastward one.

Then hand it to the Sun and Moon alignment planner with your city, and it returns every crossing for the next twelve months, grouped into windows, with the height of the Sun above the horizon at each pass. The day where that height is closest to zero is the one to put in the diary.

Two practical notes. Bearings read off a phone compass are magnetic, not true, and the two differ by up to about twenty degrees depending on where you are — enough to move the answer by weeks. And a street has two ends: 299° and 119° are the same street, one for the setting Sun and one for the rising one.

What a computed date cannot tell you

The geometry assumes a clean, flat horizon. Real cities do not have one. In Manhattan the view west runs into the New Jersey skyline, which lifts the effective horizon by a degree or so; a ridge, a hill, or a taller building further down the block does the same. The Sun therefore disappears before it reaches the geometric horizon, and the celebrated moment — the full disc resting in the street — can land a day or two off the computed peak.

Nothing in the calculation knows what is in front of you. That is why it returns a window and a height rather than a single date and a promise: the window tells you which evenings to try, and the height tells you how much margin you have against whatever is blocking your view. A pass at 1.5° will still work over a low horizon and fail over a skyline; a pass at 0.0° is as good as the geometry gets.

Weather, of course, has the final say, and the same is true of the Moon, which is dimmer, moves faster, and needs its phase to cooperate before an alignment is worth photographing.

Frequently asked questions

What counts as a “henge”?

There is no official definition. In practice people mean the days when the Sun rises or sets close enough to the horizon, and close enough to a street's axis, that it fills the corridor between the buildings. The naming convention — Manhattanhenge, Chicagohenge, Torontohenge, Baltimorehenge — follows Manhattanhenge, which popularised the idea.

Why do the dates move slightly from one year to the next?

The year is not a whole number of days, which is what leap years exist to absorb. The Sun's position on a given calendar date therefore drifts by up to a day across a four-year cycle, and the alignment drifts with it. Compute per year rather than reusing last year's dates.

Does this work for sunrise as well?

Yes, and it is the same street. Use the opposite bearing — subtract 180° if your number is above 180, add it if below. Sunrise alignments are less photographed because they are earlier, not because they are rarer.

Does it work for the Moon?

Yes. The planner takes the Moon as well as the Sun. The Moon's rising and setting points swing through a much wider arc, and repeat on a monthly rather than yearly rhythm, so most bearings get many more Moon crossings than Sun crossings. Whether any of them is worth the trip depends on the phase, which the alignment itself does not care about.

My street is not on a grid. Can I still use this?

Yes — a grid is convenient, not required. Any fixed line works: a bridge, a canal, a runway, a mountain pass, the axis of a nave. The calculation only needs the bearing of the line and where you stand.

Why does my city never align at all?

Because the bearing sits outside the Sun's arc at your latitude. A street pointing at 320° will never see a sunset in the northern half of the United States: the Sun does not get that far north. The planner says so plainly rather than returning an empty list.

Sources and further reading

• NOAA Global Monitoring Laboratory — Solar Position Calculator: azimuth and elevation of the Sun for any date, time and place.
• US Naval Observatory — Altitude and Azimuth of a Celestial Object: the reference data service for Sun and Moon positions.
• National Weather Service — Seasons: why the Sun rises due east and sets due west at the equinoxes.
• Commissioners' Plan of 1811: the survey that rotated Manhattan's grid off true north.
• Public Land Survey System: the national survey that put Chicago's streets on true north.
• Manhattanhenge: the phenomenon that named the family.