Amazon weather in short
Manaus weather is warm and humid in every month. Highs stay between 31 and 34 °C, nights between 23 and 25 °C. What changes is the rain. Manaus gets 297 to 331 mm in each month from January to April and as little as 56 mm in August. Iquitos is wetter and more even, with no month below 180 mm.
The Manaus values are monthly averages for 1991–2020. The Iquitos values are long-term averages, with rainfall from 1948 to 1994, so treat them as a guide to the pattern and not as a forecast. Neither table says anything about a specific week in 2026. If you plan a trip on the water, the season matters for routes as much as for rain. See the page on the best time to visit, and look at Amazon River cruises to see which routes run when.
Manaus weather by month
Average daily high and low, and average rainfall, 1991–2020.
| Month | High | Low | Rainfall |
|---|---|---|---|
| January | 31.3 °C | 23.6 °C | 305.6 mm |
| February | 31.1 °C | 23.6 °C | 296.8 mm |
| March | 31.2 °C | 23.7 °C | 320.9 mm |
| April | 31.3 °C | 23.7 °C | 331.0 mm |
| May | 31.5 °C | 23.9 °C | 233.3 mm |
| June | 31.9 °C | 23.8 °C | 117.2 mm |
| July | 32.5 °C | 23.7 °C | 67.1 mm |
| August | 33.6 °C | 24.1 °C | 56.1 mm |
| September | 34.1 °C | 24.5 °C | 79.0 mm |
| October | 34.0 °C | 24.6 °C | 113.9 mm |
| November | 33.0 °C | 24.4 °C | 188.0 mm |
| December | 32.0 °C | 24.0 °C | 253.5 mm |
The monthly rainfall adds up to about 2,300 mm a year. The wet months are January to April. The driest stretch is July to September, and the same months are the hottest. Drier does not mean dry: even August brings some rain. The values are averages, not records, and single days can be far hotter or wetter.
Our pick: a day on the river in any season
A day trip from Iquitos with hotel transfers and lunch; the route follows the weather.
Hand-picked tours, booked through GetYourGuide. Prices are indicative starting prices in US dollars (as of October 2026). Tap a tour for live availability and the current price in your currency.
Amazon tours and cruises through the seasons
River cruises from Iquitos and Manaus, boat trips and lodge programs, with live prices and availability.
Iquitos weather by month
Long-term averages. Rainfall 1948–1994.
| Month | High | Low | Rainfall |
|---|---|---|---|
| January | 31 °C | 22 °C | 254 mm |
| February | 30 °C | 22 °C | 245 mm |
| March | 30 °C | 22 °C | 350 mm |
| April | 30 °C | 22 °C | 330 mm |
| May | 30 °C | 22 °C | 200 mm |
| June | 29 °C | 22 °C | 180 mm |
| July | 29 °C | 21 °C | 218 mm |
| August | 30 °C | 22 °C | 220 mm |
| September | 31 °C | 22 °C | 250 mm |
| October | 31 °C | 22 °C | 270 mm |
| November | 31 °C | 22 °C | 320 mm |
| December | 31 °C | 22 °C | 250 mm |
Iquitos weather barely changes by temperature: highs of 29 to 31 °C and lows of 21 to 22 °C all year. Rain falls in every month, with the wettest stretch in March and April and the least in June. There is no dry season in the sense of a rain-free one, so pack for showers whenever you go. For the city itself, see the Iquitos guide.
Manaus and Iquitos compared
The same river, two different rain patterns.
| Manaus | Iquitos | |
|---|---|---|
| Wettest month | April, 331.0 mm | March, 350 mm |
| Driest month | August, 56.1 mm | June, 180 mm |
| Warmest month (average high) | September, 34.1 °C | January and September to December, 31 °C |
| Coolest average low | January and February, 23.6 °C | July, 21 °C |
| Period | 1991–2020 | Long-term average, rainfall 1948–1994 |
For most travelers who want the fewest rainy days, Manaus from July to September is the better bet, with the heat as the price. If you visit Iquitos or the Pacaya-Samiria reserve, plan around rain in every month and choose dates by the river and the trip you want, not by the weather alone.
What the climate means for your trip
Rain, heat and the river are three separate things.
Rain does not cancel the day
Showers are normal in the wet months and happen in the drier ones too. Bring a light rain layer and a way to keep a camera dry, and ask your operator what happens to a program in heavy rain.
The hottest months are the drier ones
In Manaus the average daily high is 33 °C or more from August to November. Plan outdoor time for the morning and late afternoon, and drink more than you expect to.
Weather is not water level
The river rises and falls on its own calendar, and cruise routes follow it. Rainfall in a given month does not tell you the water level. The best time page explains high water and low water.
Check before you book
The tables describe averages. Look at a current forecast a few days before you leave, and ask your operator how rain or river conditions can change the route.
Plan the rest of your trip
Pages that go with the weather.
Best time to visit
High water, low water and what each means for routes.
Manaus Airport and river routes
Flights to Manaus and Iquitos, slow boats and the ferry to Santa Rosa.
Where to stay
City hotel, jungle lodge or cruise cabin.
Manaus
The opera house, the museum and trips on the Rio Negro.
For more on timing across the Amazon basin, including Peru, Ecuador and Bolivia, see the best time to visit the Amazon jungle.
Amazon weather: frequently asked questions
What is the weather like in Manaus?
Hot and humid all year. Average highs run from 31.1 °C in February to 34.1 °C in September, and lows stay around 24 °C. Rain peaks from January to April, with more than 290 mm a month, and is lowest in August at 56.1 mm.
When is the rainy season in Manaus?
The wettest months are January to April, with 297 to 331 mm each. May is still wet at 233.3 mm. From June the rain drops, and July to September are the driest.
Does it rain all year in Iquitos?
Yes. The long-term averages show at least 180 mm in every month, with the most in March at 350 mm and the least in June. Showers can come in any season.
Is the dry season really dry?
No. Even in Manaus, the driest month, August, has 56.1 mm of rain on average. In Iquitos, the least wet month still has 180 mm.
Are these figures a forecast for 2026?
No. They are monthly averages, 1991–2020 for Manaus and long-term averages for Iquitos. They show the usual pattern, not what a particular week will bring.
Is amazon-river.org an official weather or tourism site?
No. This is an independent travel guide with no link to a weather service, tourism board, cruise line or tour operator.