Yellow heat warnings issued for nine mainland districts

Friday, 18 September 2026AI summary

🌱 Environment 🏖️ Daily Life #severe-weather #public-safety

Yellow heat warnings issued for nine mainland districts — Photo: RTP Notícias

The Portuguese Institute for Sea and Atmosphere (Instituto Português do Mar e da Atmosfera or IPMA) has issued Yellow Heat Warnings for nine mainland districts, including Lisbon, Porto, and Coimbra, effective from September 19 to 21, 2026. Temperatures are expected to reach 38°C due to an anticyclone, prompting officials to warn of increased rural fire risks and public health concerns.

Update: Yellow heat warnings extended until Monday evening

The IPMA has extended the duration of the yellow heat warnings for the nine affected districts until 19:00 on Monday, September 21.

Context & Explainers

A red warning is the highest alert level issued by Portugal's weather agency, the Portuguese Institute for the Sea and the Atmosphere (Instituto Português do Mar e da Atmosfera or IPMA), used when conditions pose a very high risk to life and property. Under a red warning authorities may close roads, suspend transport and advise people to avoid coastal and flood‑prone areas, so follow civil protection instructions during the Friday–Saturday storm period.