Puerto Iguazú weather in May
May in Puerto Iguazú: warm, soaked, with clean air — fine if you can take 11 rainy days.
Updated September 2026 · climate normals from ERA5 reanalysis
#5 of 12 months in Puerto Iguazú · #958 of 1413 destinations to visit in May · comfort 74/100 (tier B)
- Days
- 25°C
- Nights
- 15°C
- Wet days
- 11
- Sun
- 7.5 h
- Humidity
- 81%
- Daylight
- 11 h

Traveller notes on Puerto Iguazú in May
Puerto Iguazu-forum threads on May weather call it a genuinely strong shoulder-season month, mild afternoons that stay comfortable for a full day of walking the falls trails without the intense heat of peak summer, though mornings and evenings can feel noticeably cooler. Posters are consistent this sits toward the drier stretch of the year, blue skies fairly likely though a shower on any given day can't be ruled out entirely. Regardless of the forecast, posters are unanimous that visitors get genuinely soaked at the main viewpoints and catwalks purely from spray off the falls themselves, ponchos or a three-dollar plastic cover sold locally standard advice either way. Water levels and crowd numbers are both called favorable in May compared to the busier peak holiday stretches. The record: 25.3C days feeling like 26C, 15C nights, 81 percent humidity and 6.9 hours of sun.
Other months in Puerto Iguazú
Puerto Iguazu-forum threads on a June visit describe conditions as genuinely fine, posters calling it a little on the cold side but still nice, with a range roughly between thirteen and twenty-two degrees. Regulars call June through August genuinely the coolest, driest stretch of the year here, several posters naming this the reason conditions feel noticeably different from the humid peak season. Posters call water levels a real concern in June specifically, several regulars warning lower flow can make the falls less dramatic than wetter months. Regulars call fewer crowds and comfortable hiking real upsides of a June visit, several threads naming this a fair tradeoff against reduced water volume. Posters recommend checking recent water-level reports if seeing the falls at full force matters most, several regulars calling this standard given how much flow varies. The record: 23.7C days, 13.2C nights, 120.5mm across nearly 9 days and 81 percent humidity.
Puerto Iguazu-forum threads on an early September visit describe water levels as a genuine question mark this time of year, posters comparing conditions against summer footage to gauge whether boat rides under the falls would still be running strong. Regulars call crowds noticeably lighter in early September compared with peak season, a real advantage for anyone prioritizing space at the main viewpoints. Posters recommend two full days as a solid September stay, enough time to properly cover both the Argentine and Brazilian sides of the falls. Regulars call combining a night in Puerto Iguazu with one across the border in Foz do Iguacu a real option, several posters describing exactly this split-stay approach. Posters recommend booking border-crossing transport ahead regardless of exact dates, logistics here considered smoother with a plan in place. The record: 29.5C days feeling like 32C, 16.3C nights, an extraordinarily high 92.2mm across over 8 days and 74 percent humidity.
Puerto Iguazu-forum threads on trip planning for a March visit describe this as still squarely within the wetter season, posters calling afternoon showers a real possibility most days though rarely enough to derail a full day at the falls. Regulars call the water genuinely powerful this time of year, upstream rainfall keeping volume high across the roughly 275 individual falls in the complex. Regulars recommend the boat ride from the Argentine side for anyone wanting to get properly soaked, a dry change of clothes standing advice. Posters describe mosquito activity as a real concern some years, repellent worth packing regardless of any single forecast. Regulars call the Devil's Throat viewpoint genuinely spectacular with this much water moving through it. Posters recommend a full day for the Argentine side alone given how much trail there is. The record: 31.9C days feeling like a punishing 37C, 20.6C nights, 122.3mm across nearly 12 days and 77 percent humidity.
Puerto Iguazu-forum threads on February conditions are consistent this sits deep within the region's hot, sticky stretch, posters calling humidity itself as much a factor as the raw temperature reading. Regulars describe sun and a sudden downpour as both entirely possible within the same afternoon, the subtropical pattern here shifting fast regardless of forecast. Posters recommend real waterproof gear, a shower able to roll through the walkways with little warning. Regulars call water flow generally strong this time of year, though a heavier system can leave it visibly muddier from red clay soils upstream. Posters recommend March through May for milder, less humid conditions if flexible, February still workable for lush, green surroundings. Regulars call the falls worth the heat and humidity regardless of exact month. The record: 33.1C days feeling like a punishing 38C, 21.4C nights, an extraordinarily high 115.5mm across nearly 12 days and 76 percent humidity.
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Puerto Iguazú climate normals — May
Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.
Crowds in Puerto Iguazú in May
How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.
Shoulder seasonan ordinary month(estimated)
Peak crowdsBusyShoulder seasonQuiet
Best months for Puerto Iguazú's weather
Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).
Fair weatherPuerto Iguazú's weather peaks June–August, best around July.
Best weatherFair weatherToughest weather
What's on in Puerto Iguazú in May
Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.
- Rule
Timed park tickets, bought online
1 Jan – 31 DecBook earlyThe Argentine side sells a dated, time-slotted ticket online and the park asks you to turn up in your slot. Buying at the gate on a holiday weekend is how people end up losing a morning. Source ↗
- Opening
Full moon walk to the Garganta
1 Jan – 31 DecDark-sky seasonBook earlyThe park runs a night train and walkway trip to the Devil's Throat only on the nights around each full moon, sold separately and months ahead. It is called off when the river runs too high. Source ↗
Nearby, and something's on
Within 300 km of Puerto Iguazú — a day trip or a short hop — with something on this month. Never part of the comfort score.
Where is Puerto Iguazú?
Puerto Iguazú in May — FAQ
- Is May a good time to visit Puerto Iguazú?
- May in Puerto Iguazú: warm, soaked, with clean air — fine if you can take 11 rainy days. It ranks #5 of 12 months for Puerto Iguazú on SeasonMap's comfort score (74/100).
- What is the weather like in Puerto Iguazú in May?
- In May, Puerto Iguazú averages a daily high of 25.3°C and a low of 15°C, with about 153.2 mm of rain over roughly 10.6 rainy days.
- What is the air quality in Puerto Iguazú in May?
- Puerto Iguazú has a mean US Air Quality Index of about 24 in May.
Within 300 km: Foz do Iguaçu's Timed park tickets, booked online on 1 Jan – 31 Dec.