A Climate Baseline in Motion

Pakistan's mean annual temperature in 2024 reached 23.52°C — a departure of 0.71°C above the long-term baseline, according to Pakistan Meteorological Department's annual climate report. That figure, published in January 2025, is not a rounding error or a seasonal anomaly. It is the latest data point in a trajectory that climate scientists working on South Asian thermodynamics have been tracking for years, and it arrived alongside one of the most operationally disruptive heatwave sequences in the country's recorded meteorological history.

Then 2025 continued the pattern. Sindh province logged temperatures running 5–7°C above seasonal norms — conditions that, by any established heat-stress index, cross from "heatwave" into territory that degrades infrastructure, depresses agricultural yield, and imposes acute physiological risk across outdoor labour populations, per PMD's 2025 annual climate summary.

What Happened, and Where

The sequence unfolds across two successive years and three of Pakistan's four provinces.

In 2024, the event with the sharpest operational signature began on 23 May, when a severe heatwave descended on the plains of Punjab, Sindh, and the northeastern and southern districts of Balochistan, according to PMD's May 2024 monthly climate summary. The timing is significant: late May sits at the intersection of the pre-monsoon dry heat peak and the early agricultural stress window, when standing wheat has already been harvested but cotton and kharif crops are at early germination — a window where soil moisture is critical and heat load on irrigation infrastructure is near maximum.

Punjab's canal-irrigated plains and Sindh's lower Indus basin are not abstract geographic labels here. They are the engine rooms of Pakistan's food supply. Together they account for the overwhelming majority of the country's wheat, rice, cotton, and sugarcane output. A heatwave event centred on those zones in late May is, simultaneously, a food-security stress event, a public-health event, and a fiscal event — given that energy demand spikes, load-shedding cascades, and productivity losses in the informal sector compress household incomes precisely when resilience is needed most.

The 2025 data from Sindh adds a further layer. A 5–7°C positive anomaly is not within the range that seasonal variability can comfortably absorb. At those margins, wet-bulb temperatures in parts of lower Sindh can approach or exceed the physiological survivability threshold for unshaded outdoor activity, a concern that epidemiologists and urban planners working in Karachi have raised repeatedly since the 2015 Karachi heatwave that killed over 1,200 people.

The Baseline Problem

The 0.71°C national mean anomaly for 2024 needs to be read carefully by practitioners. Pakistan's climate baseline is already elevated compared to global averages, because the country sits at the confluence of multiple amplifying geographic factors: low-albedo alluvial plains, an arid-to-semi-arid moisture regime across most of the landmass, and the orographic channelling effect of the Hindu Kush–Karakoram–Himalaya system, which concentrates heat in the Indus basin during pre-monsoon months.

In that context, a 0.71°C departure at the national scale is a compressed metric. Regional anomalies — as the Sindh 2025 data illustrates at 5–7°C — can be dramatically larger than the national average suggests. The national mean smooths over the spatial heterogeneity that is operationally what matters. A policy official or infrastructure planner working from the national figure alone would substantially underestimate localised exposure.

We have seen this pattern before in the broader South Asian heat literature — most pointedly in the post-2010 analysis of Pakistan's compound flooding-and-heat episodes, where national-level climate summaries were systematically slower to capture sub-provincial extremes than ground-station and remotely sensed data. The institutional tendency to report upward-aggregated metrics is not unique to Pakistan, but in a country where the gap between national-average conditions and local extremes is structurally large, it carries real governance consequences.

Why the Trend Line Matters for Planning Horizons

For practitioners in sectors directly coupled to Pakistan's climate exposure — agriculture, energy, public health, insurance, and sovereign debt — the two-year sequence carries forward-looking weight beyond the individual events.

The confluence of a measurable long-run mean temperature increase (the 2024 baseline anomaly) with acute episodic extremes (the May 2024 multi-province heatwave and the 2025 Sindh anomaly) is consistent with what climate attribution science describes as the "loading the dice" mechanism: a shifted distribution in which both the mean and the variance of temperature outcomes move upward together. That means the historical return periods attached to specific heat thresholds are now systematically underestimated by models still anchored to pre-2000 baselines.

Pakistan's National Disaster Risk Reduction Policy and its NDC commitments under the Paris Agreement both acknowledge climate vulnerability. But acknowledgment and operational integration are different things. The country's heat action plans — most developed at provincial level, and of uneven technical depth — were largely calibrated against the 2015 Karachi event as a design reference. If the 2024–2025 data represents a new normal rather than a statistical outlier, those reference scenarios are already obsolete.

The Fiscal and Geopolitical Dimension

Pakistan's economic position sharpens the stakes. The country entered 2024 managing IMF programme conditionalities, a constrained current account, and energy sector circular debt that limits the government's ability to expand grid capacity in response to surging cooling demand. Heat-induced productivity losses in the agricultural sector — which accounts for roughly a quarter of GDP and a significantly larger share of rural employment — translate directly into foreign exchange pressure, given the role of cotton and rice exports.

International climate finance frameworks, including the Loss and Damage fund agreed at COP27 and operationalised through subsequent COPs, are theoretically relevant here. Pakistan is among the countries that negotiators from the Global South consistently cite as carrying disproportionate climate risk relative to historical emissions contribution. But the translation of fund architecture into disbursed, project-ready capital remains slow — a gap that practitioners working on adaptation finance in South Asia will recognise as a structural, not incidental, feature of the current multilateral system.

What the Data Does Not Yet Tell Us

The PMD reports that underpin this analysis are rigorous within their scope, but they are primarily observational summaries. They document what temperatures were recorded; they do not model forward scenarios under different emissions pathways, nor do they disaggregate health outcomes, crop loss estimates, or infrastructure damage by event. That attribution work — linking observed thermometric data to mortality, yield loss, and GDP drag — exists in peer-reviewed literature, but it is not yet systematically integrated into Pakistan's national climate reporting chain in a form that directly feeds budgetary or planning processes.

That gap is not Pakistan-specific, but closing it is arguably more urgent there than in countries with greater fiscal buffers and lower baseline exposure. The data pipeline from meteorological observation to policy-actionable risk quantification is where the next institutional investment needs to land.

Where Things Stand

As of mid-2026, Pakistan has two successive years of documented temperature extremes — the 2024 national mean anomaly and the 2025 Sindh departure — sitting in official PMD records. They confirm a pattern that climate scientists have projected but that public and institutional discourse has been slower to absorb as a planning reality rather than a future risk. The frequency and geographic spread of these events make the "unprecedented" framing increasingly untenable; what was exceptional is becoming recurrent, and recurrent events require structural response, not emergency management alone.