SØNDAG
2026-09-13
The Cloudy Brain

Too many projects, too many ideas, too few hours — one learning a day anyway

cityheatmap

Where should I head tonight — nine cities mapped by what is actually open at the hour you ask about.

Copenhagen on a Friday at 22:00: the heat surface runs orange and white along Kompagnistræde, Ravnsborggade and Vesterbrogade and cools to blue at the edges, while the panel on the right ranks the areas by name — 1. Indre By around Kompagnistræde, 379 venues with readable hours; 2. Kødbyen around Vesterbrogade, 147; 3. Nørrebro around Griffenfeldsgade, 186 — and the coverage legend in the bottom-left corner states MEASURED, NO DATA and NOT SURVEYED as separate inks and reports hours read for 1,855 of Copenhagen's 3,175 places.
FIG. 1 Copenhagen, Friday 22:00 — the surface, and the areas it ranks by name.
The same Friday 22:00 at street zoom over Copenhagen's Indre By: every place open at that hour is its own dot carrying its own name and category — Dubliner-NO5 pub, Cocks & Cows restaurant, K Cocktailbar bar, Zirup cafe, Chateau Motel Natclub nightclub, Ruby bar, Café Sorgenfri cafe — over a heat surface that burns orange through Nytorv and Amagertorv and falls to blue at the harbour, with the panel on the right saying no area centre falls in this view and that every dot here is open at this hour.
FIG. 2 Zoom in and the answer stops being a colour: the venues themselves, named.

Pick a day and an hour, and it shows which areas have the most places open — Kødbyen around Vesterbrogade, Jomfru Ane Gade, St. Pauli around Wohlwillstraße. Zoom in and you get the venues themselves, by name. It is live at cityheatmap.com.

It only counts places that publish their opening hours. If nobody wrote down when a bar opens, it isn’t on the map. That keeps it honest, but coverage varies a lot:

Hamburg 70% · Berlin 62% · Copenhagen 58% · Barcelona 25% · Palma 14%

Palma is the worst — not one of its sixteen nightclubs publishes hours. Where I know nothing, the map shows nothing.

It won’t tell you how busy a place is. Nothing I can legally use knows that.

CODElast 26 weeks · all-time 127 commits · +110k−10k lines
  • Read hours and assumed hours counted separately
  • Mallorca towns pass the hours gate
  • Real basemap under our own layers
  • Nine cities live on cityheatmap.com, phone-ready
  • Opening hours read from venue websites
  • Two screens ship; answers are named places
  • Europe pipeline: OSM extract to vector tiles
  • First design: heat as deviation, not level
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