If you’ve already put away your jacket and let yourself be lulled by the sunshine of recent days, we recommend you start looking for your umbrella because the National Weather Service (SMN) has confirmed a drastic change in the weather for Buenos Aires and the greater metropolitan area starting this Thursday, August 27. We’re sorry to say that the rains are returning and the Santa Rosa Storm is arriving early.
When will it start raining in the AMBA?
After this Wednesday, August 26—which dawned with spring-like conditions and highs reaching 18°C and 20°C—unstable weather will take over.
According to SMN radar data, the key day is Thursday, August 27. Isolated showers and downpours are expected starting in the early morning and continuing throughout the morning. Although the intensity of the storms will decrease toward the afternoon, it will be a wet day with temperatures ranging from 12°C to 19°C.
Santa Rosa Storm: When It Will Reach Buenos Aires
Popular tradition holds that the “Santa Rosa Storm” begins around August 30, coinciding with the feast day of Saint Rose of Lima. In reality, the meteorological explanation is that this phenomenon is caused by the collision of the first warm air masses—which herald the arrival of spring—with the last cold fronts of winter.
In 2026, the clash of weather fronts has come a few days early because it’s very possible that the Santa Rosa Storm will arrive on August 27 instead of August 30. So the rain doesn’t catch you off guard—whether you’re heading to the office or out on the town—here’s a detailed report to help you prepare so the Santa Rosa Storm doesn’t catch you without an umbrella:
- Wednesday, August 26: Pleasant and cloudy. Highs of 18°C/20°C. Last day to do laundry.
- Thursday, August 27 (Early Santa Rosa Day): Rain starting in the early morning and continuing through much of the morning. Conditions will improve only in the afternoon/evening. High of 19°C. Bring an umbrella!
- Friday, August 28: Goodbye to the rain. Temperatures will drop slightly (low of 10°C, high of 17°C), but the sky will be mostly clear.
