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Rio Grande weather by month: averages, rainfall & climate trends

Temperature-wise, the seasons in Rio Grande are gentle: monthly means drift only 9.8°C over the whole year. No season stands out as markedly wetter. Precipitation arrives fairly evenly year-round. Rio Grande weather by month: average temperatures, rainfall, extremes and how the climate has changed since 1940.

Today vs average

−2.6°Chigh below average

16° / 11°Today
19° / 17°Average
see today in detail →

How it's changed

+0.5°Caverage temperature, 2016–2025 vs 1940–1949average temperature vs 1940–4939days above 25°C a year now (2016–2025) · 10 in the 1940sdays above 25°C · 10 in the 1940s+0.5°C vs the 1940s · see how it's changed →
Weather by montha typical year, averaged over the full recordJanuary, rain 91 mmhigh 24°low 22°February, rain 88 mmhigh 24°low 23°March, rain 99 mmhigh 23°low 22°April, rain 107 mmhigh 21°low 19°May, rain 111 mmhigh 18°low 16°June, rain 114 mmhigh 16°low 14°July, rain 116 mmhigh 15°low 12°August, rain 113 mmhigh 15°low 13°September, rain 128 mmhigh 16°low 14°October, rain 118 mmhigh 18°low 16°November, rain 90 mmhigh 20°low 18°December, rain 80 mmhigh 22°low 20°wettest month September, 128 mm · 1,255 mm a yearsee month by month →

Right now

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

Right now

15.1°

13°feels like
72%humidity
10°dew point
15 km/hfrom S
UV index4.3
sunrise05:36sunset18:48day length13h 12m
TodayPartly cloudy16°11°
TueOvercast19°13°
WedPartly cloudy20°15°
ThuOvercast19°16°
FriOvercast21°17°
SatPartly cloudy24°14°
SunMostly clear23°16°

On this date: October 26

Today (forecast)
16° / 11°
Average for October 26
19° / 17°

High below average · −2.6°C

  • Highest since 1940: 24.1° · 1959
  • Lowest since 1940: 12.5° · 1949
  • One year ago: 21° / 17°

Every October 26 in history, coldest to hottest

▲ Daily highs▼ Daily lows

Dots show daily highs (top) and lows (bottom) for each October 26 on record (n = 87). 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 Rio Grande is sampled from the ECMWF ERA5 reanalysis at 32.03°S, 52.10°W, with daily records since 1940.

Coordinates
32.03°S, 52.10°W
Time zone
America/Sao Paulo
Period
1940–2026
Data source
ERA5 (ECMWF)

Last 30 days

9 of the last 31 days were warmer than the historical average for that date. Average difference: −0.9°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 year peaks in February, at around 24.2°C by mid-afternoon, with nights around 22.5°C. Around 135 nights a year stay above 20°C. At the other extreme, July brings afternoon highs of about 14.8°C and typical overnight lows of 12.5°C. Freezing temperatures almost never occur.

The yearly total for Rio Grande comes to about 1,255 mm; monthly amounts range from 80 mm in December up to 128 mm in September.

Over the full record (since 1940), the annual mean temperature in Rio Grande has risen by 0.5°C between its first decade and its last. The count of days past 25°C has risen from roughly 10 a year to 40 between the record's first and last decades.

Climate graph (climograph)

February is the warmest month, July the coolest: a yearly swing of 10°C. Wettest month: September (~128 mm). Whole year averages ~1,255 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 95 rainy days a year: most in September (~9), fewest in December (~6).

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.

Rio Grande 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
January23.7°22.1°91 mm713.9 h30.7° (2019)16.0° (1945)
February24.2°22.5°88 mm813.1 h30.9° (2025)15.8° (2023)
March23.5°21.7°99 mm812.2 h29.6° (2025)14.5° (2012)
April21.3°19.3°107 mm811.2 h27.4° (2018)10.2° (1999)
May18.4°16.3°111 mm810.4 h24.8° (1982)8.0° (2007)
June16.0°13.6°114 mm99.9 h22.8° (2023)5.7° (2025)
July14.8°12.5°116 mm910.1 h22.3° (1973)5.0° (2007)
August15.1°12.8°113 mm810.8 h22.9° (2014)5.4° (1972)
September16.1°14.0°128 mm911.8 h23.5° (1977)6.9° (1972)
October18.0°16.1°118 mm812.8 h25.3° (2014)9.0° (1972)
November20.2°18.2°90 mm713.7 h27.2° (1968)11.5° (1992)
December22.2°20.4°80 mm614.1 h29.1° (2012)13.6° (1982)

How it's changed

Year-by-year signals from 1940 to today.

Climate stripes

Annual mean shifted from 1940–1949 to 2016–2025 by +0.5°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: +0.07°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

Sep–Nov is warming fastest: +0.13°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 ≥ 25°C per year: 9.8 early in the record → 38.9 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 2025, coldest in 2007: 30.9°C / 5.0°C.

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

Annual rainfall

~1,255 mm/year on average. Last decade: +1% vs that average. Long-term trend: +27 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 Rio Grande

Which is the warmest month in Rio Grande?
On long-term average, the warmest month in Rio Grande is February (mean daily temperature of about 23.3°C) and the coolest is July (about 13.6°C).
How does today's temperature in Rio Grande compare to the historical average?
On October 26, 2026, Rio Grande is forecast to reach a high of 16.4°C and a low of 11.3°C. The long-term average for this date (the full record since 1940) is a high of 19.0°C and a low of 17.0°C, so today's high is 2.6°C cooler than that average.
How much has Rio Grande warmed since 1940?
Comparing the first decade of the record (1940–1949) with the most recent (2016–2025), the annual mean temperature in Rio Grande is about 0.5°C warmer.
How much does it rain in Rio Grande?
Rio Grande receives about 1,255 mm of precipitation per year on long-term average, with September typically the wettest month.
What is the average temperature in Rio Grande?
Over the full record (since 1940), the annual mean temperature in Rio Grande is about 18.4°C. The warmest month is February and the coolest is July.
What are the average temperatures in Rio Grande by month?
Average daily highs and lows for each month in Rio Grande (°C, full record since 1940): January 24°/22°, February 24°/23°, March 23°/22°, April 21°/19°, May 18°/16°, June 16°/14°, July 15°/12°, August 15°/13°, September 16°/14°, October 18°/16°, November 20°/18°, December 22°/20°.
What is the weather like in Rio Grande in summer?
December to February is summer in Rio Grande, and it is pleasantly warm. Daytime highs sit at 22–24°C and nights at 20–23°C; February is the warmest month. Rain is steady at around 86 mm a month, spread over roughly 7 days. It is the driest season of the year.
What is the weather like in Rio Grande in winter?
In winter, June through August, Rio Grande is wet and fairly mild. Afternoons run 15–16°C and nights 12–14°C; July is the coldest month. Rain falls on about 9 days a month, adding up to around 114 mm.
What is the weather like in Rio Grande in spring?
Spring in Rio Grande (September to November) is wet and mild. September starts at 16°C by day and 14°C at night; by November it is 20°C and 18°C. Rain is steady at around 112 mm a month, spread over roughly 8 days.
What is the weather like in Rio Grande in autumn?
In autumn, March through May, Rio Grande is wet and mild. March still brings 23°C afternoons and 22°C nights, May only 18°C and 16°C. Rain falls on about 8 days a month, adding up to around 106 mm.
How many days a year does it rain in Rio Grande?
On long-term average, Rio Grande has about 95 days a year with at least 2 mm of rain or snow. The annual total is roughly 1,255 mm.

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