# Extreme heat and low humidity in Cuiabá > Live situation record from CLSTR: https://clstr.news/situations/extreme-heat-and-low-humidity-in-cuiab > Updated: 2026-09-12T21:29:00.000Z. Sources: 9. Developments: 3. Cuiabá, Brazil, experienced extreme weather conditions characterized by temperatures exceeding 40°C and critically low relative humidity, which reached as low as 11%. In response to these conditions, meteorological alerts were issued for the Mato Grosso region, and hydration initiatives were launched to assist vulnerable populations. As the extreme heat and high ultraviolet radiation persisted, the Cuiabá Municipal Health Secretariat implemented operational changes for Community Health Agents (ACS). Following the VIGIAR Weekly Bulletin No. 25/2026, which classified the local climate as dangerous, home visits and external activities were restricted to the morning hours (7:00 AM to 11:00 AM). During the afternoon, agents transitioned to internal administrative tasks, such as population registry updates, at Family Health Units to mitigate health risks. Following this period of intense heat, which saw temperatures reach 41°C, the city experienced a significant temperature drop. Minimum temperatures fell to between 21°C and 23°C, accompanied by increased cloud cover and reduced direct sunlight. While these milder conditions provided relief, the National Institute of Meteorology (Inmet) noted that potential danger remains due to fluctuating relative humidity, which is expected to range between 15% and 90%. ## Claims - The Cuiabá Municipal Health Secretariat has implemented temporary changes to the routine of Community Health Agents (ACS). (corroborated by 5 sources) - The VIGIAR Weekly Bulletin No. 25/2026 classified meteorological conditions in Cuiabá as dangerous due to high temperatures, low humidity, and high UV radiation. (corroborated by 5 sources) - Community Health Agents must perform home visits and external activities preferably between 7:00 AM and 11:00 AM. (corroborated by 5 sources) - From 1:00 PM to 5:00 PM, agents will prioritize internal activities at Family Health Units (USFs), such as administrative tasks and population registration updates. (corroborated by 5 sources) ## Timeline ### 2026-09-12: Cuiabá experiences temperature drop after extreme heat Cuiabá saw a significant temperature drop this Sunday, with lows around 21°C-23°C providing relief after recent extreme heat reaching 41°C. 2 sources. https://clstr.news/cluster/cuiab-experiences-temperature-drop-after-extreme-heat ### 2026-08-31: Cuiabá adjusts health agent routines due to extreme heat Cuiabá has adjusted the work schedules of Community Health Agents to protect them from extreme heat, low humidity, and high UV radiation, moving outdoor visits to morning hours. 7 sources. https://clstr.news/cluster/cuiab-adjusts-health-agent-routines-due-to-extreme-heat ### 2026-08-18: Cuiabá records extreme heat and record low humidity Cuiabá, Brazil, recorded extreme heat of 40.2°C and a national low humidity of 11%. Meanwhile, EPAL launched a hydration guidance initiative to assist with heatwave management. 3 sources. https://clstr.news/cluster/cuiab-records-extreme-heat-and-record-low-humidity --- Cite as: Extreme heat and low humidity in Cuiabá. CLSTR, https://clstr.news/situations/extreme-heat-and-low-humidity-in-cuiab