New survey data from the Association for Project Management (APM) suggests that the recent UK heatwave had a widespread impact on project delivery, with 96% of 1,008 UK-based project professionals saying their main project was affected. This guest article has more…
This included over 6 in 10 (64%) who said their project was affected significantly by the heatwave, underlining a clear warning: climate change is already disrupting delivery, and projects that are not designed for more frequent extreme weather face a growing risk of delay, cost escalation or failure.
Among those respondents reporting an impact, the most common consequences of the heatwave* were changed working hours, such as earlier starts or later finishes (25% of responses), projects being postponed or temporarily paused (24%), heat affected materials or equipment (23%), health and safety measures were increased (23%), outdoor work had to be suspended or reduced (22%) and reduced productivity due to extreme temperatures (21%).
Other heatwave consequences cited by respondents included delayed deliveries or supplies, additional costs, revised deadlines, missed deadlines, and staff wellbeing or heat-related absences.
Other findings across selected industry sectors** from the survey – carried out for APM by Censuswide – show how the heatwave created different pressures across project environments including:
- Construction: 99% of those project professionals working in the sector said their projects were affected, including 62% significantly. Among those affected, 28% reported schedule delays causing missed deadlines, 26% increased health and safety measures, and 25% said projects had to be postponed or paused.
- Energy: 99% said their projects were affected, including 65% significantly. Among those affected, 30% reported changed working hours, 26% said projects were postponed or paused, and 22% reported reduced productivity or revised deadlines.
- Engineering: 96% said their projects were affected, with 68% significantly affected. The biggest reported impacts included reduced outdoor work at 36%, changed working hours at 32%, and reduced productivity at 27%.
- Transport and logistics: 98% said their projects were affected, including 57% significantly. Key impacts included materials or equipment affected by heat at 27%, postponed or paused projects at 25%, and reduced outdoor work at 26%.
The findings also point to an urgent need for stronger resilience across these sectors. Overall, 77% of project professionals said the heatwave had made them more confident their organisation’s future projects will be resilient to extreme weather events, but 18% said they were now less confident.
Project professionals working in construction were more cautious than the average (18%) on future resilience, with 24% saying they are less confident that their organisation’s future projects will be resilient against impacts from extreme weather events.
For organisations delivering major infrastructure, buildings, energy systems and transport networks, preparedness can no longer be treated as a future consideration; it is becoming a core test of whether projects will be deliverable at all.
Standout findings include widespread operational effects across working hours, safety measures, materials and equipment, outdoor work, productivity and project schedules. They also reinforce the need for organisations to move from reactive contingency planning to proactive climate preparedness, so that extreme weather – such as heatwaves – is properly built into project scope, budgets, risk registers, procurement, workforce planning and delivery schedules.
Dr Hugo Minney, Network Lead of APM’s Sustainability Interest Network, says: “The message for organisations is that climate change is now a delivery risk and a cost risk, not a distant environmental issue. Project leaders can mitigate against these risks in three practical ways: carry out climate-specific risk assessments at the start of every project; build informed flexibility into schedules, contracts, budgets and supply chains; and protect the workforce through robust heat, safety and wellbeing plans.

“This is not simply about responding better when disruption occurs. It is about designing projects that can continue to deliver in the conditions they are likely to face. Organisations that fail to take this seriously may find that extreme weather exposes weaknesses in planning, procurement and governance, with consequences for cost, confidence and completion.”
Notes
*Respondents to the survey were asked to select ‘all that applied’ to the impact the heatwave had on the main project(s) they were working on
**The sectors surveyed by Censuswide for APM were Construction, Education, Energy, Engineering, Financial Services, Healthcare & Pharmaceuticals, HR, Legal, Manufacturing, Public Sector & Local Government, Retail, Catering & Leisure, Sales, Media and Marketing, Space, Technology, Telecoms
Responses rounded to the nearest 1%




