Weather and climate in Rosario (Argentina)

The climate of Rosario is subtropical (according to the Köppen classification, on the border between the subtropical climate with dry winter - Cwa, and the humid subtropical climate - Cfa), with mild, quite dry winters (from mid-May to mid-August) and hot, rainy summers (from December to February). In summer, the rains often occur in the form of thunderstorms.
The city is located in the Pampa Argentina, in the province of Santa Fe, at 33 degrees south latitude and 300 km (185 miles) northwest of Buenos Aires. We are on the west bank of the Paraná River, which on the other side widens into an area occupied by swamps and islands.



Even though the winter is mild, there can sometimes be periods a bit cold, especially at night, when the temperature can drop to around freezing or a little below.
Snow in Rosario is extremely rare, however, in July 2007 there was a light snowfall, while the only real snowfall with accumulation occurred in July 1973.
During the day it can get hot all year round, in fact, the heat records are around 30 °C (86 °F) even in winter, in July and August. On the other hand, from September to February, there can be heat waves, in which the temperature reaches 38/40 °C (100/104 °F).
But the Pampero, the south wind, is able to interrupt the hot and muggy periods, bringing pleasant temperatures (and sometimes even very cool) for two or three days.

Best Time

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It is difficult to find the best time to visit Rosario, also because there can be sudden changes in temperature. Anyway, you can choose the period from mid-April to mid-May, in which both temperature and rainfall are halfway between winter and summer.
Winter, from mid-May to mid-August, is the mildest and driest season of the year, but sometimes it can get cold, especially at night.
In spring, starting from mid-August, it can be very hot, although it depends on the years. Summer is the sunniest season, but it is hot and muggy, and thunderstorms can break out.

Rosario - Climate data

The average temperature of the coldest month (July) is of 10.7 °C (51.3 °F), that of the warmest month (January) is of 24.8 °C (76.6 °F). Here are the average temperatures.
Precipitation amounts to 1055 millimeters (41.5 inches) per year: it is therefore quite abundant. It ranges from 23 mm (0.9 in) in the driest month (July) to 138 mm (5.4 in) in the wettest one (March). Here is the average precipitation.
There are on average around 2615 sunshine hours per year. Here are the average hours of sunshine per day.

Rosario - Weather by month

Based on the period 1991-2020

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January, the warmest month of the year, is generally a warm to hot month. The average temperature is of 24.8 °C (77 °F), with a minimum of 18.7 °C (65.7 °F) and a maximum of 30.9 °C (87.6 °F).
On the coldest nights of the month, the temperature usually drops to around 11.5 °C (53 °F). However, it dropped to 8.6 °C (47.5 °F) in January 2020.
On the warmest days of the month, the temperature usually reaches around 36.5 °C (98 °F). However, it reached 40.5 °C (104.9 °F) in January 2006.
Precipitation amounts to 121 mm (4.8 in), distributed over 6 days.
The day lasts on average 14 hours and 0 minutes.
There are on average 9.5 hours of sunshine per day. So, the sun shines 68% of the time.
The average humidity is 65%.
The average wind speed is 12 kph (7 mph).

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February is generally a warm to hot month. The average temperature is of 23.6 °C (74 °F), with a minimum of 17.7 °C (63.9 °F) and a maximum of 29.4 °C (84.9 °F).
On the coldest nights of the month, the temperature usually drops to around 10.5 °C (51 °F). However, it dropped to 6.9 °C (44.4 °F) in February 2003.
On the warmest days of the month, the temperature usually reaches around 35 °C (95.5 °F). However, it reached 39.3 °C (102.7 °F) in February 2003.
Precipitation amounts to 127 mm (5 in), distributed over 7 days.
The day lasts on average 13 hours and 10 minutes.
There are on average 8.5 hours of sunshine per day. So, the sun shines 65% of the time.
The average humidity is 70%.
The average wind speed is 11 kph (7 mph).

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March is generally a warm month. The average temperature is of 21.8 °C (71 °F), with a minimum of 16 °C (60.8 °F) and a maximum of 27.7 °C (81.9 °F).
On the coldest nights, the temperature usually drops to around 8 °C (47 °F). However, it dropped to 4.2 °C (39.6 °F) in March 2012.
On the warmest days, the temperature usually reaches around 34 °C (93 °F). However, it reached 36.5 °C (97.7 °F) in March 2020.
Precipitation amounts to 138 mm (5.4 in), distributed over 6 days.
The day lasts on average 12 hours and 10 minutes.
There are on average 7.5 hours of sunshine per day. So, the sun shines 62% of the time.
The average humidity is 72%. Hence, the air is normally humid.
The average wind speed is 11 kph (7 mph).

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April is generally a warm month. The average temperature is of 18.2 °C (65 °F), with a minimum of 12.4 °C (54.3 °F) and a maximum of 23.9 °C (75 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 3.5 °C (38.5 °F). However, it dropped to -0.9 °C (30.4 °F) in April 2016.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 31 °C (88 °F). However, it reached 36 °C (96.8 °F) in April 2018.
Precipitation amounts to 120 mm (4.7 in), distributed over 7 days.
The day lasts on average 11 hours and 10 minutes.
There are on average 6 hours of sunshine per day. So, the sun shines 55% of the time.
The average humidity is 75%. Hence, the air is normally humid.
The average wind speed is 11 kph (7 mph).

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May is generally a very mild month. The average temperature is of 14.8 °C (59 °F), with a minimum of 9.4 °C (48.9 °F) and a maximum of 20.1 °C (68.2 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 0.5 °C (33 °F). However, it dropped to -5.7 °C (21.7 °F) in May 2008.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 27.5 °C (81.5 °F). However, it reached 32.9 °C (91.2 °F) in May 1997.
Precipitation amounts to 58 mm (2.3 in), distributed over 4 days.
The day lasts on average 10 hours and 25 minutes.
There are on average 5.5 hours of sunshine per day. So, the sun shines 54% of the time.
The average humidity is 79%. Hence, the air is normally humid.
The average wind speed is 11 kph (7 mph).

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June is generally a mild month. The average temperature is of 11.6 °C (53 °F), with a minimum of 6.2 °C (43.2 °F) and a maximum of 17 °C (62.6 °F).
On the coldest nights, the temperature usually drops to around -3 °C (26.5 °F). However, it dropped to -6.7 °C (19.9 °F) in June 2017.
On the warmest days, the temperature usually reaches around 24 °C (75 °F). However, it reached 29 °C (84.2 °F) in June 2005.
Precipitation amounts to 28 mm (1.1 in), distributed over 3 days.
The day lasts on average 10 hours and 0 minutes. June 21, the winter solstice, is the shortest day of the year in the Southern Hemisphere.
There are on average 5 hours of sunshine per day. So, the sun shines 49% of the time.
The average humidity is 78%. Hence, the air is normally humid.
The average wind speed is 11 kph (7 mph).

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July, the coldest month of the year, is generally a mild month. The average temperature is of 10.7 °C (51 °F), with a minimum of 4.9 °C (40.8 °F) and a maximum of 16.5 °C (61.7 °F).
On the coldest nights of the month, the temperature usually drops to around -3.5 °C (25.5 °F). However, it dropped to -8.4 °C (16.9 °F) in July 2020.
On the warmest days of the month, the temperature usually reaches around 25.5 °C (78 °F). However, it reached 31.6 °C (88.9 °F) in July 2008.
Precipitation amounts to 23 mm (0.9 in), distributed over 3 days.
The day lasts on average 10 hours and 10 minutes.
There are on average 5.5 hours of sunshine per day. So, the sun shines 55% of the time.
The average humidity is 75%. Hence, the air is normally humid.
The average wind speed is 12 kph (8 mph).

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August is generally a mild month. The average temperature is of 12.8 °C (55 °F), with a minimum of 6.3 °C (43.3 °F) and a maximum of 19.2 °C (66.6 °F).
On the coldest nights of the month, the temperature usually drops to around -2.5 °C (27.5 °F). However, it dropped to -7.8 °C (18 °F) in August 1995.
On the warmest days of the month, the temperature usually reaches around 28.5 °C (83.5 °F). However, it reached 35 °C (95 °F) in August 1996.
Precipitation amounts to 35 mm (1.4 in), distributed over 3 days.
The day lasts on average 11 hours and 0 minutes.
There are on average 6.5 hours of sunshine per day. So, the sun shines 57% of the time.
The average humidity is 69%.
The average wind speed is 13 kph (8 mph).

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September is generally a very mild month. The average temperature is of 15.1 °C (59 °F), with a minimum of 8.7 °C (47.7 °F) and a maximum of 21.5 °C (70.7 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 0 °C (32.5 °F). However, it dropped to -3.4 °C (25.9 °F) in September 2019.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 30.5 °C (87 °F). However, it reached 37.3 °C (99.1 °F) in September 2013.
Precipitation amounts to 48 mm (1.9 in), distributed over 4 days.
The day lasts on average 11 hours and 55 minutes.
There are on average 6.5 hours of sunshine per day. So, the sun shines 55% of the time.
The average humidity is 65%.
The average wind speed is 15 kph (9 mph).

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October is generally a warm month. The average temperature is of 18.3 °C (65 °F), with a minimum of 12.3 °C (54.1 °F) and a maximum of 24.3 °C (75.7 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 4 °C (39.5 °F). However, it dropped to 0.6 °C (33.1 °F) in October 1999.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 32.5 °C (91 °F). However, it reached 38 °C (100.4 °F) in October 2014.
Precipitation amounts to 119 mm (4.7 in), distributed over 8 days.
The day lasts on average 13 hours and 0 minutes.
There are on average 7 hours of sunshine per day. So, the sun shines 55% of the time.
The average humidity is 67%.
The average wind speed is 15 kph (10 mph).

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November is generally a warm month. The average temperature is of 21.2 °C (70 °F), with a minimum of 15 °C (59 °F) and a maximum of 27.5 °C (81.5 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 8 °C (46.5 °F). However, it dropped to 1.8 °C (35.2 °F) in November 1992.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 35 °C (94.5 °F). However, it reached 39.4 °C (102.9 °F) in November 2020.
Precipitation amounts to 108 mm (4.3 in), distributed over 7 days.
The day lasts on average 13 hours and 50 minutes.
There are on average 9 hours of sunshine per day. So, the sun shines 64% of the time.
The average humidity is 63%.
The average wind speed is 15 kph (9 mph).

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December is generally a warm to hot month. The average temperature is of 23.6 °C (74 °F), with a minimum of 17.3 °C (63.1 °F) and a maximum of 29.8 °C (85.6 °F).
On the coldest nights of the month, the temperature usually drops to around 10.5 °C (51 °F). However, it dropped to 6.2 °C (43.2 °F) in December 2010.
On the warmest days of the month, the temperature usually reaches around 36 °C (96.5 °F). However, it reached 39.6 °C (103.3 °F) in December 1995.
Precipitation amounts to 128 mm (5 in), distributed over 8 days.
The day lasts on average 14 hours and 20 minutes. So the days are long. December 21, the summer solstice, is the longest day of the year in the Southern Hemisphere.
There are on average 9.5 hours of sunshine per day. So, the sun shines 65% of the time.
The average humidity is 63%.
The average wind speed is 13 kph (8 mph).