Rosario weather in January
In January, Rosario has daytime highs averaging 30 °C, nights around 20 °C, with 8.1 wet days. Figures are 1991–2020 climate normals.
- 30.1°C Average high
- 20.2°C Average low
- 8.1days Wet days
- 103mm Rainfall
- 14h Daylight
Daily temperatures through January
How January 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 January | 30.1 °C | 20.2 °C | 27 % |
| 11–20 January | 29.8 °C | 19.8 °C | 26 % |
| 21–31 January | 30.2 °C | 20.6 °C | 25 % |
What to expect
| Measure | Typical January | Share of the month |
|---|---|---|
| Days above 25 °C | 29 of 31 | 94 % |
| Days above 30 °C | 16 of 31 | 51 % |
| Days below 0 °C | 0 of 31 | 0 % |
| Days with more than 1 mm rain | 8.1 of 31 | 26 % |
Conditions in January
| Measure | Average |
|---|---|
| Mean temperature | 25 °C |
| Record high (1991–2020) | 39 °C |
| Record low (1991–2020) | 12 °C |
| Relative humidity | 65 % |
| Wind speed | 16 km/h |
| Cloud cover | 38 % |
January compared with the months around it
| Month | Avg high | Rainfall | Cloud |
|---|---|---|---|
| January | 30.1 °C | 103 mm | 38 % |
| February | 28.5 °C | 111 mm | 41 % |
| March | 26.6 °C | 125 mm | 40 % |
| November | 26.3 °C | 113 mm | 42 % |
| December | 28.8 °C | 106 mm | 41 % |
See all twelve months for Rosario
- January is the warmest month in Rosario.
- It is the 6th driest month of the year.
- It ranks 1st for least cloud cover.
- Days last about 14 hours from sunrise to sunset.
- It rains on 8.1 of 31 days — 26 % of the month.
- Nights are about 9.9 °C cooler than the middle of the day.
- The hottest January day on record since 1991 reached 39 °C, 8.9 °C above the usual daytime high.
QuestionsJanuary in Rosario, answered
How warm is Rosario in January?
Daily highs average 30 °C and nights fall to about 20 °C, a spread of 9.9 °C between afternoon and dawn. That makes January the 1st warmest month of the year here.
Does it rain much in Rosario in January?
January averages 103 mm of rain, spread over about 8 of the 31 days — 26 % of the month. Cloud cover averages 38 % of the sky.
How long are the days in January?
Rosario averages 14 hours between sunrise and sunset in January. 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.