Viamão climate

Name: Viamão
Address: BR

Viamão is warmest in January, with average highs of 28 °C, and coldest in July, when nights average 10 °C. October is the wettest month (173 mm) and April the driest (105 mm). Figures are 1991–2020 climate normals.

Across a full year Viamão averages 1,553 mm of rain and 150 days above 25 °C.

Brazil · population 231,996 · 1991–2020 normals

Temperature below 0 °C to above 30 °C Rain band height is that month’s share of the wettest month

Warmest month January 28 °C
Coldest month July 10 °C
Driest month April 105 mm
Wettest month October 173 mm
Least cloud March 52 % cloud
Hottest on record December 39 °C
Coldest on record June 0.2 °C

What to expectViamão through the year

Viamão has a clear annual cycle: average daily highs run from 18 °C in July to 28 °C in January, a swing of 10 °C in mean temperature across the year.

Counted across a normal year, 150 days a year reach 25 °C, 34 of them reach 30 °C. The warmest reading in the 1991–2020 record is 39 °C, in December.

Rain is spread fairly evenly through the year, from 105 mm in April to 173 mm in October. There is no dry season to aim for.

Month by month

Month	Avg high	Rainfall	Cloud
January	28.4 °C	138 mm	56 %
February	28.1 °C	129 mm	56 %
March	26.9 °C	121 mm	52 %
April	24.4 °C	105 mm	55 %
May	20.7 °C	107 mm	59 %
June	18.7 °C	116 mm	61 %
July	18.1 °C	139 mm	58 %
August	20.0 °C	123 mm	55 %
September	20.9 °C	149 mm	61 %
October	23.1 °C	173 mm	64 %
November	25.2 °C	124 mm	54 %
December	27.6 °C	129 mm	54 %

Temperature month by month

Month	Avg high	Avg low	Mean	Record high	Record low	Days above 25 °C	Days above 30 °C
January	28.4 °C	20.6 °C	24.1 °C	38.0 °C	12.7 °C	27	9
February	28.1 °C	20.7 °C	24.0 °C	37.3 °C	12.2 °C	24	7
March	26.9 °C	19.5 °C	22.7 °C	37.1 °C	9.4 °C	22	4
April	24.4 °C	16.8 °C	20.2 °C	32.7 °C	6.8 °C	12	2
May	20.7 °C	13.5 °C	16.7 °C	29.5 °C	3.9 °C	4	0
June	18.7 °C	11.2 °C	14.5 °C	28.7 °C	0.2 °C	2	0
July	18.1 °C	10.2 °C	13.7 °C	28.7 °C	0.2 °C	2	0
August	20.0 °C	11.3 °C	15.1 °C	31.8 °C	1.2 °C	5	0
September	20.9 °C	13.0 °C	16.5 °C	34.1 °C	2.9 °C	5	1
October	23.1 °C	15.4 °C	18.8 °C	35.7 °C	7.6 °C	9	1
November	25.2 °C	16.9 °C	20.7 °C	37.0 °C	9.2 °C	14	3
December	27.6 °C	19.2 °C	23.0 °C	38.6 °C	10.8 °C	24	7

Rain, sun and wind month by month

Month	Rainfall	Wet days	Daylight	Cloud cover	Humidity	Wind
January	138 mm	14	14 h/day	56 %	77 %	18 km/h
February	129 mm	14	13 h/day	56 %	78 %	17 km/h
March	121 mm	12	12 h/day	52 %	79 %	17 km/h
April	105 mm	10	11 h/day	55 %	80 %	16 km/h
May	107 mm	9	11 h/day	59 %	82 %	15 km/h
June	116 mm	9	10 h/day	61 %	83 %	15 km/h
July	139 mm	10	10 h/day	58 %	82 %	16 km/h
August	123 mm	10	11 h/day	55 %	81 %	16 km/h
September	149 mm	11	12 h/day	61 %	80 %	18 km/h
October	173 mm	12	13 h/day	64 %	80 %	19 km/h
November	124 mm	11	14 h/day	54 %	77 %	19 km/h
December	129 mm	12	14 h/day	54 %	75 %	19 km/h

How Viamão compares

The same four figures for nearby destinations, so the numbers above have something to be read against. Summer high is the warmest month's average high; winter low is the coldest month's average low.

Destination	Summer high	Winter low	Rain per year	Days above 25 °C
Viamão	28 °C	10 °C	1,553 mm	150
Porto Alegre · Brazil	29 °C	10 °C	1,542 mm	170
Novo Hamburgo · Brazil	29 °C	9.4 °C	1,732 mm	165
Caxias do Sul · Brazil	25 °C	7.3 °C	2,002 mm	78

Where Viamão ranks

Ranking	Position	Value
Places with the best weather in South America in October	45thof 50	82/100

Planning a trip? See the best time to visit Viamão.

QuestionsCommon questions about Viamão’s climate

When is the best time to visit Viamão?

That depends on what you want, so the honest answer is a comparison rather than a single month. April, October, November sit closest to 20 °C on average, January is the warmest month and April the driest. The month-by-month table above has the full picture.

How hot does Viamão get?

In January, the warmest month, daily highs average 28 °C. About 34 days a year pass 30 °C. The highest value in the 1991–2020 record is 39 °C.

How cold does it get in winter?

Nights average 10 °C in July, the coldest month. Freezing nights are not part of a normal year here.

Which month is wettest in Viamão?

October, averaging 173 mm over 12 days with rain. The driest month is April with 105 mm. The year as a whole averages 1,553 mm.

Are these figures a forecast?

No. They are 1991–2020 climate normals: the average of thirty years, which describes what a month is usually like in Viamão rather than what any particular week will bring. Individual years can differ substantially from the normal.

Data sources and method

ERA5 / ERA5-Land reanalysis — Copernicus Climate Change Service (C3S), ECMWF. Copernicus Licence
Open-Meteo — Open-Meteo.com. CC BY 4.0
NOAA OISST v2.1 — NOAA Physical Sciences Laboratory. Public domain
GeoNames — GeoNames.org. CC BY 4.0

Normal period: 1991–2020
Dataset version: era5-1991-2020-scores1.1
Last processed: 1 August 2026

Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: monthly rankings, daylight hours, beach and comfort scores. Full formulas are on the methodology page.

Contains modified Copernicus Climate Change Service information 2026. Neither the European Commission nor ECMWF is responsible for any use that may be made of the Copernicus information or data it contains.