The Water Woes of Tehran: A Looming Crisis

In the summer of 2025, Iran found itself in the grip of a severe heatwave, with temperatures in various areas, including Tehran, inching towards 122 degrees Fahrenheit. The intense heat led to the shutdown of public institutions and financial establishments. Concurrently, the water reserves feeding the Tehran area shrunk to unprecedented lows. By the onset of November, the water level in Amir Kabir Dam, a pivotal water supply for the city, had plummeted dramatically. This dire situation highlights not only the extraordinary warmth of the season but also multiple years of declining rain and pervasive drought conditions affecting Iran, positioning Tehran on the brink of a 'Day Zero' scenario where water availability could completely cease.

The drought swiftly permeated Tehran’s infrastructure. With soil moisture evaporating and reservoir levels dropping, water scarcity imposed stringent conservation measures throughout the city. Increasing concerns arose when officials warned that without a substantial recovery in water sources, Tehran might witness severe repercussions. President Masoud Pezeshkian, in November, remarked on the critical situation. The cascading events have emphasized Tehran’s vulnerability, where environmental pressures have illuminated fragilities within its infrastructure, economy, and populace.

The root of these issues lies in a sustained lack of rainfall over recent years. Normally, Tehran experiences its wettest months from December to April, ensuring reservoir replenishment before the parched months. However, for the last five years, rainfall during this period hasn't reached normative levels. The rain season of 2024-25 was especially stark, registering shortages throughout. Pairing this prolonged dry spell with an exceptionally hot summer exacerbated water strain.

The extended precipitation shortfall was not isolated to Tehran but part of a regional anomaly affecting much of Iran. Satellite analyses from late 2024 to early 2025 exposed a clear precipitation dipole: enhanced rainfall north of 40° N but substantial declines across central and southern Iran. Particularly affected was a broad swath extending from the eastern Mediterranean through Iran, where diminished storm activity drastically cut reservoir inflows, worsening the existing water crisis.

Projected climate change impacts indicate way more decline in regional precipitation over the Mediterranean. Researchers, including Alexandre Tuel and Elfatih Eltahir, have focused on why this area has become a climate change focal point. Their studies foresee significant declines in winter and spring precipitation extending into Mesopotamia under high-emission scenarios by century’s end.

Another influence is the shift in spring storm tracks due to predicted changes in air currents caused by climate change, pushing storm tracks northward. This northward shift means less rain southward where Tehran lies. This aligns with IPCC projections indicating dry conditions might become normal in future springs.

Tehran's region is a transitional zone experiencing varied storm systems, differing from winter to spring. While models disagree on winter precipitation projections, more research is essential to discern natural climate variations and future climate impacts.

The severe drought and heat of this year in Tehran were unparalleled, keeping in line with predictions that similar events will increase with global warming. Without intervention, Tehran faces a perilous future of frequent droughts, reduced water supply, and threats to public health, energy, and food security. These findings highlight urgent risks tied to climate change, underscoring the need for global emissions cuts and local adaptive strategies to mitigate growing threats.