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Foz do Iguaçu weather by month: averages, rainfall & climate trends

Temperature-wise, the seasons in Foz do Iguaçu are gentle: monthly means drift only 9.1°C over the whole year. Rainfall is spread quite evenly across the year. Foz do Iguaçu weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

−0.9°Chigh near average

27° / 22°Today
28° / 18°Average
see today in detail →

How it's changed

+0.8°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–49146days above 30°C a year now (2016–2025) · 63 in the 1940sdays above 30°C · 63 in the 1940s+0.8°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 172 mmhigh 31°low 22°February, rain 155 mmhigh 31°low 22°March, rain 139 mmhigh 30°low 21°April, rain 137 mmhigh 27°low 18°May, rain 149 mmhigh 24°low 15°June, rain 132 mmhigh 22°low 14°July, rain 110 mmhigh 23°low 13°August, rain 104 mmhigh 25°low 14°September, rain 154 mmhigh 26°low 16°October, rain 204 mmhigh 28°low 18°November, rain 159 mmhigh 30°low 20°December, rain 178 mmhigh 31°low 22°wettest month October, 204 mm · 1,794 mm a yearsee month by month →

Right now

What it's doing today vs the historical average for this date.
Overcast

Right now

23.2°

24°feels like
51%humidity
13°dew point
4 km/hfrom E
UV index0.0
sunrise05:58sunset18:47day length12h 50m
TodayShowers27°22°
ThuOvercast25°21°
FriOvercast33°21°
SatThunderstorm25°23°
SunOvercast23°17°
MonMostly clear26°13°
TueOvercast25°18°

On this date: October 21

Today (forecast)
27° / 22°
Average for October 21
28° / 18°

High near average · −0.9°C

  • Highest since 1940: 37.6° · 2015
  • Lowest since 1940: 9.8° · 1976
  • One year ago: 28° / 15°

Every October 21 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 21 on record (n = 86). Outlined dots are today's forecast.

Area we sample

Each city's history comes from one ERA5 grid cell, about 28 km across, shown by the dashed box. Near mountains or coasts, conditions can vary across the cell.

Location & data

Historical weather for Foz do Iguaçu is sampled from the ECMWF ERA5 reanalysis at 25.55°S, 54.59°W, with daily records since 1940.

Coordinates
25.55°S, 54.59°W
Time zone
America/Sao Paulo
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

11 of the last 30 days were warmer than the historical average for that date. Average difference: −0.1°C.

Each bar is one day, from morning low to afternoon high. Warm-colored bars are days whose mean ran above average; cool bars ran below. The dot inside the bar is the daily mean. The shaded band is the typical 10–90% range expected for that date. Average = the day's mean temperature averaged across every year of record (1940–2026) for that calendar date.

This date over the years

One dot per year, showing the mean temperature on this calendar date. Dots are warmer or cooler than the long-term average (dashed line); the shaded band is the typical 10–90% range, and the highlighted dot is today's forecast. Based on ERA5 reanalysis: modelled estimates, not station readings.

Weather by month

Average temperatures and rainfall for each month: a typical year, from the full record.

Climate overview

The warmest month is January, with typical afternoon highs of 31.0°C and nights around 22.5°C. On about 170 nights a year, the temperature never drops below 20°C. In July, the coolest month, afternoons reach about 22.5°C and nights dip to 13.3°C.

The yearly total for Foz do Iguaçu comes to about 1,794 mm; monthly amounts range from 104 mm in August up to 204 mm in October. Precipitation falls on roughly 122 days in a typical year.

Comparing the record's first decade with its most recent one, Foz do Iguaçu now averages 0.8°C warmer than it did in the 1940s. Days above 30°C have grown noticeably more frequent, from around 65 a year in the first decade to about 145 in the last.

Climate graph (climograph)

January is the warmest month, July the coolest: a yearly swing of 9°C. Wettest month: October (~204 mm). Whole year averages ~1,794 mm of rain.

Bars = average monthly rainfall (right axis). Lines = average daily high and low (left axis). Average = each month's value averaged across every year of record (1940–2026).

Rainy days by month

About 122 rainy days a year: most in January (~14), fewest in August (~7).

Bars = average number of days with ≥ 2 mm per month. Hover for the monthly rainfall total.

Monthly wind

Average daily peak wind at 10 m, by month.

Monthly solar energy

Average daily incoming solar energy in megajoules per square metre: the record's own proxy for how sunny the month is.

Foz do Iguaçu month by month: what to expect

Typical conditions for each month, averaged across the full record (since 1940). Daylight is the time from sunrise to sunset. Highest and Lowest are the most extreme values in the ERA5 dataset (modelled since 1940), so they can differ from official weather-station readings.

MonthAvg highAvg lowRainRainy daysDaylightHighestLowest
January31.0°22.5°172 mm1413.4 h39.3° (2022)13.3° (1980)
February30.7°22.3°155 mm1312.9 h38.0° (2014)12.2° (2023)
March29.9°21.2°139 mm1112.2 h38.2° (2005)9.2° (1976)
April27.3°18.4°137 mm811.4 h35.6° (2005)5.6° (1999)
May23.9°15.4°149 mm810.8 h33.7° (2024)2.5° (2007)
June22.2°14.0°132 mm810.4 h30.6° (2024)1.1° (2012)
July22.5°13.3°110 mm710.6 h31.3° (2016)−1.6° (1975)
August24.6°14.5°104 mm711.1 h35.5° (1995)1.3° (1991)
September26.3°16.3°154 mm911.9 h39.4° (2020)2.8° (1980)
October28.1°18.5°204 mm1212.6 h39.9° (2020)6.8° (1981)
November29.6°19.8°159 mm1013.3 h40.6° (1942)7.7° (2022)
December30.7°21.6°178 mm1313.6 h40.5° (1985)10.9° (2010)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +0.8°C.

Each vertical stripe is one year. Color encodes how much that year's annual mean differed from the long-term average. Average = each year's annual mean compared to the average of all years (1940–2026). cooler ← → warmer

Annual mean temperature

Long-term trend: +0.12°C per decade.

One point per year, showing the temperature averaged across the whole year. The dashed line is the least-squares long-term trend. Based on ERA5 reanalysis: modelled estimates, not station readings.

Seasonal warming

Dec–Feb is warming fastest: +0.15°C per decade.

Each faint line is one three-month period's average per year; the bold dashed line is its long-term trend. Different parts of the year often warm at different rates. Based on ERA5 reanalysis: modelled estimates, not station readings.

Hot days vs frost days

Days ≥ 30°C per year: 63.3 early in the record → 145.9 recently. Frost days: 0 → 0.

Thin lines are raw yearly counts; thick lines are the smoothed trend that removes year-to-year noise. The hot-day threshold is auto-picked per city so the line actually moves. Average = a centered 5-year rolling average to smooth weather noise.

Yearly hot & cold extremes

Hottest day since 1940 in 1942, coldest in 1975: 40.6°C / −1.6°C.

One point per year: the single hottest and coldest day recorded that year.

Annual rainfall

~1,794 mm/year on average. Last decade: −15% vs that average. Long-term trend: −13 mm per decade.

One bar per year of total rainfall. Dashed line is the long-term average. Average = the average annual rainfall across every year of record (1940–2026).

Day-by-day grid

Each tiny square is one calendar day across the full record, about 30,000 days per city. Use the mode switch above the chart: Anomaly colors each day by how far it ran from the historical average for that date (red = warmer, blue = cooler), Daily mean temp shows the absolute mean temperature for the day (useful to see seasons and heatwaves), and Precipitation shows daily rainfall (useful to spot wet/dry seasons and droughts). Average = the long-term average for that calendar date (1940–2026).

Frequently asked questions about Foz do Iguaçu

Which is the warmest month in Foz do Iguaçu?
On long-term average, the warmest month in Foz do Iguaçu is January (mean daily temperature of about 26.3°C) and the coolest is July (about 17.2°C).
How does today's temperature in Foz do Iguaçu compare to the historical average?
On October 21, 2026, Foz do Iguaçu is forecast to reach a high of 26.9°C and a low of 21.8°C. The long-term average for this date (the full record since 1940) is a high of 27.8°C and a low of 18.4°C, so today's high is 0.9°C cooler than that average.
How much has Foz do Iguaçu warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Foz do Iguaçu is about 0.8°C warmer.
How much does it rain in Foz do Iguaçu?
Foz do Iguaçu receives about 1,794 mm of precipitation per year on long-term average, with October typically the wettest month.
What is the average temperature in Foz do Iguaçu?
Over the full record (since 1940), the annual mean temperature in Foz do Iguaçu is about 22.2°C. The warmest month is January and the coolest is July.
What are the average temperatures in Foz do Iguaçu by month?
Average daily highs and lows for each month in Foz do Iguaçu (°C, full record since 1940): January 31°/22°, February 31°/22°, March 30°/21°, April 27°/18°, May 24°/15°, June 22°/14°, July 23°/13°, August 25°/14°, September 26°/16°, October 28°/18°, November 30°/20°, December 31°/22°.
What is the weather like in Foz do Iguaçu in summer?
December to February is summer in Foz do Iguaçu, and it is wet and hot. Daytime highs sit at 31°C and nights at 22°C; January is the warmest month. Rain is steady at around 168 mm a month, spread over roughly 13 days.
What is the weather like in Foz do Iguaçu in winter?
June to August is winter in Foz do Iguaçu, and it is wet and pleasantly warm. Afternoons run 22–25°C and nights 13–14°C; July is the coldest month. Rain falls on about 8 days a month, adding up to around 116 mm.
What is the weather like in Foz do Iguaçu in spring?
September to November is spring in Foz do Iguaçu, and it is wet and warm. September is still 26°C in the afternoon and 16°C at night, November already 30°C and 20°C. Rain is steady at around 172 mm a month, spread over roughly 10 days.
What is the weather like in Foz do Iguaçu in autumn?
Autumn in Foz do Iguaçu (March to May) is wet and warm. March still brings 30°C afternoons and 21°C nights, May only 24°C and 15°C. Rain falls on about 9 days a month, adding up to around 142 mm.
How many days a year does it rain in Foz do Iguaçu?
On long-term average, Foz do Iguaçu has about 122 days a year with at least 2 mm of rain or snow. The annual total is roughly 1,794 mm.

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