Montevideo weather in August
In August, Montevideo has daytime highs averaging 15 °C, nights around 9.6 °C, with 7.8 wet days, and a sea temperature of 12 °C. Figures are 1991–2020 climate normals.
- 14.8°C Average high
- 9.6°C Average low
- 7.8days Wet days
- 94mm Rainfall
- 11.9°C Sea temperature
- 11h Daylight
Daily temperatures through August
How August develops
Averages for the first, middle and last part of the month, from daily 1991–2020 normals. Chance of rain is the share of years in which that calendar day recorded more than 1 mm.
| Days | Avg high | Avg low | Chance of rain |
|---|---|---|---|
| 1–10 August | 13.7 °C | 8.9 °C | 25 % |
| 11–20 August | 15.0 °C | 9.5 °C | 24 % |
| 21–31 August | 15.7 °C | 10.2 °C | 26 % |
- Average highs rise from 13.7 °C early in August to 15.7 °C by the end of it.
What to expect
| Measure | Typical August | Share of the month |
|---|---|---|
| Days above 25 °C | 0.3 of 31 | 1 % |
| Days above 30 °C | 0 of 31 | 0 % |
| Days below 0 °C | 0 of 31 | 0 % |
| Days with more than 1 mm rain | 7.8 of 31 | 25 % |
Conditions in August
| Measure | Average |
|---|---|
| Mean temperature | 12 °C |
| Record high (1991–2020) | 27 °C |
| Record low (1991–2020) | 0.8 °C |
| Relative humidity | 78 % |
| Wind speed | 22 km/h |
| Cloud cover | 56 % |
Where Montevideo ranks in August
| Ranking | Position | Value |
|---|---|---|
| The coolest places in South America in August | 11th of 50 | 15 °C |
| The coolest places in the world in August | 28th of 50 | 15 °C |
August compared with the months around it
| Month | Avg high | Rainfall | Cloud |
|---|---|---|---|
| June | 14.2 °C | 81 mm | 59 % |
| July | 13.1 °C | 86 mm | 58 % |
| August | 14.8 °C | 94 mm | 56 % |
| September | 15.9 °C | 84 mm | 55 % |
| October | 18.5 °C | 115 mm | 55 % |
See all twelve months for Montevideo
- August is the 10th warmest month here.
- It is the 7th driest month of the year.
- It ranks 9th for least cloud cover.
- Days last about 11 hours from sunrise to sunset.
- It rains on 7.8 of 31 days — 25 % of the month.
- Nights are about 5.2 °C cooler than the middle of the day.
- The hottest August day on record since 1991 reached 27 °C, 12 °C above the usual daytime high.
- Beach score: 18 / 100 — see how this is calculated.
QuestionsAugust in Montevideo, answered
How warm is Montevideo in August?
Daily highs average 15 °C and nights fall to about 9.6 °C, a spread of 5.2 °C between afternoon and dawn. That makes August the 10th warmest month of the year here.
Does it rain much in Montevideo in August?
August averages 94 mm of rain, spread over about 8 of the 31 days — 25 % of the month. Cloud cover averages 56 % of the sky.
Is the sea warm enough to swim in August?
The sea averages 12 °C off Montevideo in August. Most people find water below 20 °C bracing and above 25 °C comfortable for a long swim; this figure is a monthly surface average, so a sheltered bay on a still afternoon can be warmer.
How long are the days in August?
Montevideo averages 11 hours between sunrise and sunset in August. Day length is computed from latitude and date, so it is exact rather than modelled — but it says nothing about how much of that time is sunny.
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
Measured values come from ERA5 reanalysis and are reproduced unchanged. Calculated by us: daylight hours, beach and comfort scores, monthly rankings, threshold day counts, chance of a wet day by date, ten-day averages within the month. 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.