Climate Art · Traditional Architecture × Modern Heat
The Shadow of the Moucharabieh
How traditional lattice screens process climate data — and how +1.6°C is rewriting the algorithm.
A moucharabieh is a carved wooden lattice screen that has regulated light, air, and privacy in Moroccan homes for centuries. It is an analogue climate processor: the input is solar radiation and temperature; the output is habitable shadow. At dawn the lattice breathes open. At midday it contracts — its star-shaped apertures tightening to filter the hammer of the sun. Morocco has warmed +1.6°C since 1990. In Ouarzazate, July peaks breach 39°C. The lattice that once sufficed is being tested by heat its builders never imagined.
+1.6°C
warming since 1990
39.5°C
July peak, Ouarzazate
3,534h
sunshine hours / year
1mm
July rain, Marrakech
The Living Lattice
Select a city, month, and drag the hour. The star apertures contract as temperature rises — the lattice “closes” at peak heat. At dawn, it opens to breathe.
35.7°C
exterior temp
30%
aperture open
Hot
heat stress
Marrakech · Jul · 15:00
24-Hour Temperature — Marrakech, Jul
Marrakech · BSh — Semi-arid · 460m
Jul range: 19.9°C → 36.8°C · Swing: 16.9°C
Sunshine: 10.8h/day · Rain: 1mm
Three Climates, One Country
Monthly highs, colour-coded by heat stress. Ouarzazate enters “Very Hot” in June; Tangier never does.
Solar Radiation Calendar
Average daily sunshine hours. The lattice works hardest where the sun burns longest.
Marrakech
Tangier
Ouarzazate
The +1.6°C Problem
The moucharabieh was designed for a cooler century. Traditional cooling is approaching its limits.
Traditional Cooling vs Modern Heat
Moucharabieh lattice
Filters light, channels air through star apertures
Passive — cannot reduce below ambient
Effective range: < 35°C
Riad courtyard + fountain
Evaporative cooling, thermal mass, stack ventilation
Water scarcity undermining the effect
Effective range: < 38°C
Pisé walls (60 cm)
8–12 hour thermal lag delays peak heat to evening
Rising night temps prevent full discharge
Effective range: < 40°C if night < 22°C
Wind tower (badgir)
Passive ventilation via pressure differential
Needs > 10°C diurnal swing — shrinking
Effective range: < 42°C with swing
Morocco Average Temperature by Decade
WMO 1991–2000 average from 5 stations
Gradual warming. Drought years increasing.
Heat records broken across interior.
August 2023 warmest month on record (27.9°C avg).
The moucharabieh was calibrated for a world 1.6°C cooler. In Ouarzazate, the July diurnal swing (21°C → 39.5°C = 18.5°C range) still allows thick walls to work — heat absorbed by day radiates at night. But as minimum temperatures rise, the “reset window” shrinks. When nights stay above 25°C, traditional thermal mass cannot fully discharge. The architecture stops breathing.
Reading Notes
The Lattice as Algorithm
A moucharabieh is not decoration. It is a passive climate algorithm: input (solar angle, wind direction), parameters (hole size, wood density, screen depth), output (filtered light, directed airflow, privacy). The craftsman who carved it was performing thermal modelling by hand, calibrated over generations. Each city had its own lattice density — Marrakech denser than Tangier, Ouarzazate densest of all.
Why Tangier Survives
Tangier's July peak (30°C) stays within the “Warm” threshold. The Atlantic moderates extremes. Traditional architecture still works here. In Marrakech and Ouarzazate, where peaks hit 37–40°C, passive cooling approaches its limits. The cities that need traditional design most are the ones where it is failing first.
The 2030 Projection
At current warming rates, Marrakech will average 38°C+ in July by the 2030s. Ouarzazate will regularly exceed 41°C. The World Cup will be played in air-conditioned stadiums while the medinas, built for a cooler century, adapt or overheat. The moucharabieh is not obsolete — it is a blueprint for bio-inspired design. But it needs augmentation: hybrid systems combining passive lattice with targeted mechanical cooling.
The moucharabieh is not a window. It is a question: how much light do you need? How much heat can you bear? For centuries, the answer was carved in cedar. Now the question is changing faster than wood can be cut. The lattice closes a little more each decade — not because the craftsman adjusted it, but because the sun grew louder. At some temperature, the holes close entirely. That is the threshold Morocco is approaching.
Sources
Monthly climate data: WMO 1991–2020 normals via ClimateToTravel, Weather Atlas, Climate-Data.org. Marrakech (Jul high 36.8°C): Weather Atlas. Tangier (Aug high 30.1°C): Weather Atlas. Ouarzazate (Jul high ~39.5°C): ClimateToTravel. Warming trend (+1.6°C since 1990): WorldData.info analysis of German Weather Service (DWD) stations. Annual sunshine (3,534h): Climate-Data.org Marrakech. Aug 2023 record (27.9°C avg): WorldData.info. Heat Stress Index thresholds adapted from WHO/WMO guidelines. Traditional cooling effectiveness: editorial estimates based on Fathy (1986), Pearlmutter (2007), Santamouris (2016). Moucharabieh design: Al-Jayyousi (2003), Ragette (2012). Hourly curves are sinusoidal models calibrated to monthly min/max — not station-level observations.
© Dancing with Lions