Study estimates Britain’s June heatwave cost pupils 15 million lesson hours

Heat disrupted more than 1,700 schools

Pupils in England and Wales missed at least 15 million hours of teaching during Britain’s June heatwave, according to a new analysis reported by the Guardian. The study identified more than 1,700 schools that closed completely or ended lessons early and estimated that at least 760,000 children lost classroom time. Some schools recorded indoor temperatures above 40C.

The estimate combines reported closures with census and official attendance data. That methodology means the total is best understood as a minimum rather than a complete administrative count. The researchers also found that absences rose in schools that remained open, as some families kept children home because of heat-related concerns. Staff described headaches, nausea, fainting and sharply reduced concentration.

Official data confirms an exceptional attendance shock

Department for Education statistics provide an independent measure of the disruption in England. Attendance fell to 88.13 percent in the week beginning June 22, producing an absence rate of 11.87 percent. That was 5.06 percentage points above the equivalent week in 2025. The department explicitly cautioned that the figures coincided with exceptional heat and amber and red heat-health alerts.

The official data does not attribute every absence to temperature, and illness remained an important category. It nevertheless records a clear break from the year’s prevailing pattern: absence had been about 7 percent immediately after the late-spring half-term before climbing to nearly 11.9 percent during the heatwave week. That supports the conclusion that extreme conditions caused a substantial education shock.

Adaptation becomes a public-investment question

Current government guidance says schools should remain open where safe, using lighter clothing, drinking water, shaded areas, timetable changes, ventilation and cooler rooms. Temporary closure is permitted where conditions are unsafe, with remote education considered where practical. Those instructions also reveal the policy tension: keeping schools open protects learning, meals and social support, but older buildings may not be designed for sustained extreme heat.

The government says it is funding school renewal and rebuilding, while teachers and education specialists are calling for faster adaptation. The policy test is whether retrofits can reduce overheating without diverting already constrained classroom budgets. Future heat alerts will show whether updated guidance, ventilation work and estate investment can prevent another nationwide loss of teaching time on this scale.