Fer & Vent Climb forecast · Paris
Light · blue hour

Thirty minutes of indigo

The blue hour is shorter than its name suggests — about thirty minutes in Paris — and it is the single most photographed half-hour from the summit of the tower.

What produces it

In the half-hour after sunset the sun is below the geometric horizon but still above the atmospheric horizon. Light travelling from the sun through the upper atmosphere scatters off ozone and dust and reaches us as a diffuse blue. Below this diffuse glow, Paris starts to light up — street lamps, café fronts, bridge lanterns. The sum of the two is the characteristic deep-blue sky and warm-glow Paris of blue-hour photographs.

Timing

In Paris, the true civil blue hour runs from about 10 minutes after sunset to about 35 minutes after sunset. The sky then darkens into astronomical twilight; the light balance tips too far towards the city and the sky becomes an indifferent black. On the summit, we aim to arrive on the deck at sunset + 5 minutes and leave at sunset + 40.

The sparkle

At the top of every hour after dark, the tower produces its sparkle — 20,000 flash-bulbs embedded in the lattice fire for five minutes. If you are on the deck during the sparkle you do not see the effect from outside, obviously, but the lower-platform photographs are famous for a reason. If you want the sparkle inside your blue-hour photograph of the tower, you need to be outside the tower — at the Trocadéro, the Champ-de-Mars, or the Pont de Bir-Hakeim — looking at it.

A quick decision guide

  • Blue hour from the summit — go up, catch the whole thing, descend before the deck closes. Best for seeing the city turn on.
  • Blue hour from the ground, including sparkle — do not go up. Stand at the Trocadéro gardens (M° Trocadéro) and face the tower. The sparkle at 20:00 or 21:00 in winter is the postcard moment.
  • Both — climb for golden hour and the first half of blue hour, descend, walk to the Trocadéro for the top-of-the-hour sparkle. This is the three-hour visit most of our readers choose.

Phone photography

Phones have grown good at low light. The usual trap is motion blur, not noise. Lean the camera against a horizontal bar on the deck; count to three before releasing the virtual shutter; take three shots in a row and keep the sharpest. Avoid phone flash — it will light the railing closest to you, nothing else.

What can go wrong

Low-level cloud cover kills the blue — the sky stays grey and the city lights look dull. A clear or lightly veiled sky is best. We flag the forecast on the daily note.