Climate averages 1991–2020
Rosario weather
in December.
A hot, wet month: the 2nd warmest and the 8th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
December is a hot month in Rosario: daytime highs average 28.8°C and nights cool to about 18.5°C. By daytime temperature it is the 2nd warmest of the 12 months.
Expect about 104 mm of rain on roughly 9 days, which makes December a wet month (the 8th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 14 h 17 min on an average December day.
The nearest other city in this atlas is Gobernador Gálvez (9 km away). In December its highs average 28.7°C, about as warm as Rosario, with 104 mm of rain.
Among the 67 cities listed in Argentina, Rosario ranks joint 25th of 67 for the warmest December highs and joint 43rd of 67 for the driest December (rainfall, lowest first). The mean December high of those 67 cities is 27.9°C; Rosario is 0.9°C warmer than that mean.
From December to January, average highs rise by 1.2°C to 30.0°C, and monthly rainfall falls from 104 mm to 102 mm.
The annual picture
December in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Rosario climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 30.0°C20.1°C | 20.1°C | 102 | 8.1 | 14.114 h |
| February | 28.4°C19.3°C | 19.3°C | 113 | 8.5 | 13.313 h |
| March | 26.6°C17.5°C | 17.5°C | 126 | 7.6 | 12.312 h |
| April | 22.7°C14.1°C | 14.1°C | 103 | 7.9 | 11.311 h |
| May | 18.8°C11.1°C | 11.1°C | 66 | 6.0 | 10.510 h |
| June | 16.0°C8.1°C | 8.1°C | 40 | 4.6 | 10.010 h |
| July | 15.4°C6.9°C | 6.9°C | 36 | 5.0 | 10.210 h |
| August | 18.1°C8.1°C | 8.1°C | 53 | 4.6 | 10.911 h |
| September | 20.4°C10.1°C | 10.1°C | 61 | 5.8 | 11.912 h |
| October | 23.2°C13.1°C | 13.1°C | 111 | 9.7 | 12.913 h |
| November | 26.3°C15.8°C | 15.8°C | 115 | 8.3 | 13.814 h |
| December, selected | 28.8°C18.5°C | 18.5°C | 104 | 8.6 | 14.314 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
December in nearby cities
- Gobernador Gálvez in DecemberArgentina · 9 kmHigh 28.7°C · Low 18.6°C · 104 mm rain
- San Nicolás de los Arroyos in DecemberArgentina · 59 kmHigh 28.4°C · Low 18.6°C · 108 mm rain
- Pergamino in DecemberArgentina · 105 kmHigh 28.2°C · Low 17.5°C · 107 mm rain
- Paraná in DecemberArgentina · 135 kmHigh 28.8°C · Low 19.1°C · 128 mm rain
- Santa Fe in DecemberArgentina · 144 kmHigh 29.2°C · Low 19.5°C · 136 mm rain
- Venado Tuerto in DecemberArgentina · 152 kmHigh 28.3°C · Low 17.9°C · 115 mm rain
- Junín in DecemberArgentina · 185 kmHigh 28.0°C · Low 17.2°C · 103 mm rain
- Zárate in DecemberArgentina · 197 kmHigh 28.0°C · Low 17.4°C · 104 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Rosario) is explained once on the Rosario year overview and on the Sources, method and limits page.
Gobernador Gálvez lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.