Iran Geography & Climate

Iran is large — about 1.65 million square kilometres, bigger than France, Germany, Spain and Italy combined — and most of it is an elevated plateau at between a thousand and fifteen hundred metres, ringed by mountains that trap the moisture outside.

Two mountain ranges

The Zagros runs diagonally down the west for some fifteen hundred kilometres. The Alborz curves along the northern edge, carrying Damavand at 5,610 metres — a dormant volcano and the highest peak in the Middle East, visible from Tehran on a clear day.

Two deserts

The interior basins hold the Dasht-e Kavir, a salt desert with a crust over mud, and the Dasht-e Lut, which is UNESCO-listed and where satellites have recorded some of the highest land surface temperatures ever measured. Its kaluts are wind-carved ridges running for over a hundred kilometres.

The Caspian exception

North of the Alborz, the narrow Caspian littoral is humid, densely populated and covered in the Hyrcanian forest, a relic woodland twenty-five to fifty million years old and a UNESCO natural site. It grows rice, tea and citrus, and it looks nothing like the rest of the country.

The south

The Persian Gulf and Gulf of Oman coasts are hot and humid, with the islands of Qeshm, Hormuz and Kish offshore, and salt domes that push up through the rock in extraordinary colours.

Water and quakes

Iran is in a severe water crisis: Lake Urmia, once the largest lake in the Middle East, has largely dried. The country is also seismically very active, and earthquakes have repeatedly destroyed cities, including Bam in 2003.

Iran’s climate is dominated by altitude and by the mountain ranges that keep moisture out of the interior. Most of the country is arid or semi-arid, with a very wide gap between day and night and between summer and winter.

The plateau

Tehran, Isfahan, Yazd and Shiraz sit high enough that summers are hot and dry rather than humid — 35 to 40°C in July — and winters are genuinely cold, with snow in Tehran most years and freezing nights across the desert cities.

The deserts

The Kavir and the Lut are extreme in both directions: above 45°C by day in summer and near freezing on winter nights, with almost no rainfall at all. The diurnal range in the desert is the thing that catches visitors out.

The Caspian coast

North of the Alborz the picture reverses entirely: humid subtropical, with over a metre of rain a year in places, mist in the forest, and mild winters. It is the wettest part of the country by a wide margin.

The south

The Gulf coast is hot and very humid. Ahvaz and Bandar Abbas in summer combine temperatures above 45°C with high humidity, producing some of the most punishing conditions anywhere that people live.

Mountains

The Alborz and Zagros hold snow from December to April, with ski resorts above Tehran at Dizin and Shemshak reaching over three thousand metres. Damavand keeps snow year round.

Dust and drought

Dust storms affect the west and south-west, worsened by drying wetlands in Iraq and Iran alike, and the country’s long-term drought is the most consequential environmental fact about it.