Manaus weather in December

Forum posters describe January as squarely in Manaus's hot, wet season, with heavy rain a genuine daily possibility, but posters are consistent that seeing the sun at some point during the day is more likely than not - a full day of nonstop rain is unusual. Posters describe a typical pattern as sun during the day with rain, often heavy, moving in during the afternoon and cooling temperatures down a little. Posters flag that particularly strong storms can occasionally lead tour operators to cancel excursions, though it's impossible to predict in advance which specific days will be severe enough for that. One visitor's mid-January river cruise saw real rain and cloud cover but still had plenty of dry windows for jungle excursions. Posters generally rate January as workable for an Amazon visit despite the wet-season label, with flexible planning around afternoon rain the key adjustment.

July is the dry season in Manaus, though the forum's regulars are careful with the word: it is hot and humid always, just not unbearable, and the record still shows rain on about fourteen days. Days run near 31°C and the nights barely drop, to 24. The reason July is recommended is water rather than sky — the best cruising falls at the late end of the rains, roughly April to July, when levels are high, many trees are in bloom, and animals feed in the treetops where you can actually see them. That flooded-forest experience is what June and July buy you. Later in the dry season, November into December, the river runs low.