Key Takeaways:
- Petrolina expected to see high temperatures up to 37°C and relative humidity between 20% and 30% through to the end of the year.
- Local authorities from SESPU and APAC issue health and safety guidance including hydration, sun protection and humidifying indoor spaces.
- WHO recommends ideal indoor humidity of 60–80%; residents are advised to reduce diuretics such as coffee and alcohol.
- Defence Civil is available 24/7 via WhatsApp at (87) 98134-1838 for urgent assistance.
Petrolina, in the São Francisco sertão of Pernambuco, is expected to endure several days of intense heat and very low humidity, with temperatures forecast to climb to around 37°C and relative humidity falling to between 20% and 30% until the end of the year, according to a notice from the Pernambuco Agency for Water and Climate (APAC).
Petrolina low humidity: what residents should know
The municipal Secretariat for Public Services and Civil Defence (SESPU) has issued guidance to help residents reduce health risks associated with the conditions. Authorities recommend keeping well hydrated, using sunscreen and moisturising creams, and avoiding strenuous physical exertion during the hottest hours of the day. Lightweight clothing, hats and sunglasses are advised for anyone needing to be outdoors.
APAC’s advisory stresses that very low relative humidity increases the risk of dehydration, skin and eye irritation, and can exacerbate respiratory symptoms for those with pre-existing conditions. The World Health Organization suggests an ideal relative humidity for human health is between 60% and 80%; levels forecast for Petrolina are substantially below that range.
To mitigate indoor dryness, SESPU suggests humidifying enclosed spaces where possible. Simple measures such as placing bowls of water near fans, using damp towels, or operating household humidifiers can improve comfort and reduce mucous membrane irritation. People are also encouraged to limit intake of diuretic beverages, including coffee and alcohol, which can increase dehydration risk.
Officials have emphasised public safety as the city approaches New Year’s Eve festivities along the waterfront. The municipality has published event details and logistics separately, and reminded residents to follow guidance from civil defence and health services. For urgent assistance related to weather or public-safety issues, Petrolina’s Defence Civil can be contacted 24 hours a day via WhatsApp on (87) 98134-1838.
Local authorities urge employers and community organisers to consider altering schedules for outdoor work or events to avoid the hottest parts of the day. Those who must undertake physical tasks outside are advised to increase rest breaks, maintain hydration, and wear appropriate sun protection.
Health services note particular concern for vulnerable groups, including older adults, young children and people with chronic illnesses. These groups should be monitored closely for signs of heat stress — such as dizziness, excessive sweating followed by a lack of sweating, headache, confusion, or a rapid pulse — and should seek medical attention if symptoms worsen.
The weather advisory is part of routine seasonal monitoring in the region, which commonly experiences hot and dry conditions during the Brazilian summer months. Residents are encouraged to follow local forecasts and official channels for updates, and to adopt the simple precautions recommended by SESPU and APAC to reduce health risks until humidity and temperatures return to more typical levels.

















