Clima em Armação dos Búzios em setembro

September opens the Rio spring and regulars sell it on two things at once: beach temperatures by day with comfortable nights, and beaches that are not crowded because this is low season. They put the month at 22 to 30C with little rain and some of the clearest blue skies of the year - useful when the thing you have come to see is on top of a mountain. Our row gives 28.5C reading as 31C, 59.9mm across 8.5 days and 9.1 hours of sun. The sea is cooler now at 23.3C. The record: 20.1C nights, humidity 74 percent, a 12.4 kph wind and AQI 70.

Búzios' forum generally likes October - pleasant spring temperatures, mostly blue skies, and genuinely low crowds in the first half of the month before an October 12-15 holiday period brings a short price and crowd spike. One quirk worth knowing before picking a beach: the northern beaches (Tartaruga, Azeda, João Fernandes) catch warmer currents while the southern ones (Geribá, Tucuns) run noticeably colder, and an occasional cold-water upwelling from further south can chill things further. Posters treated this as normal, not a reason to avoid the month - just something to factor into which beach to pick.

Forum posters describe April daytime highs typically in the upper-70s to low-80sF (roughly 27-28C), cooling to a comfortable 70F (21C) at night - genuinely pleasant beach weather with lower humidity than the more oppressive summer months. Posters call April the tail end of high season rather than truly low season: prices have come down from peak, beaches are noticeably less crowded, but the town isn't dead either. Landing between Easter and Brazil's mid-April national holiday (the 21st), posters consistently name this as a strong sweet-spot window - cooler, drier, and quieter than peak summer, without yet losing all the energy of the high season crowd.