Climate - Rosario (Argentina)

The climate of Rosario is subtropical, 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

In Rosario, the average temperature of the coldest month (July) is of 10.9 °C (51.6 °F), that of the warmest month (January) is of 25.2 °C (77.3 °F). Here are the average temperatures.
In Rosario, precipitation amounts to 1020 millimeters (40.2 inches) per year: it is therefore quite abundant. It ranges from 25 mm (1 in) in the driest month (July) to 145 mm (5.7 in) in the wettest one (March). Here is the average precipitation.
In Rosario, there are on average around 2745 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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In January, the hottest month of the year, the weather in Rosario is usually warm to hot. The average temperature is of 25.2 °C (77 °F), with a minimum of 18.7 °C (65.6 °F) and a maximum of 31.7 °C (89 °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 110 mm (4.3 in), distributed over 8 days.
The day lasts on average 14 hours and 0 minutes.
There are on average 10 hours of sunshine per day. So, the sun shines 72% of the time.
The average humidity is 65%.
The average wind speed is 12 kph (7 mph).

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In February, the weather in Rosario is usually warm to hot. The average temperature is of 23.9 °C (75 °F), with a minimum of 17.6 °C (63.8 °F) and a maximum of 30.2 °C (86.4 °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 120 mm (4.7 in), distributed over 8 days.
The day lasts on average 13 hours and 10 minutes.
There are on average 9.5 hours of sunshine per day. So, the sun shines 74% of the time.
The average humidity is 70%.
The average wind speed is 11 kph (7 mph).

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In March, the weather in Rosario is usually warm. The average temperature is of 22.1 °C (72 °F), with a minimum of 15.9 °C (60.6 °F) and a maximum of 28.4 °C (83.2 °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 145 mm (5.7 in), distributed over 8 days.
The day lasts on average 12 hours and 10 minutes.
There are on average 8 hours of sunshine per day. So, the sun shines 65% 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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In April, the weather in Rosario is usually warm. The average temperature is of 18.6 °C (65 °F), with a minimum of 12.3 °C (54.2 °F) and a maximum of 24.9 °C (76.7 °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 110 mm (4.3 in), distributed over 8 days.
The day lasts on average 11 hours and 10 minutes.
There are on average 7 hours of sunshine per day. So, the sun shines 64% 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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In May, the weather in Rosario is usually very mild. The average temperature is of 14.9 °C (59 °F), with a minimum of 8.9 °C (48.1 °F) and a maximum of 20.8 °C (69.5 °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 60 mm (2.4 in), distributed over 5 days.
The day lasts on average 10 hours and 25 minutes.
There are on average 6 hours of sunshine per day. So, the sun shines 59% 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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In June, the weather in Rosario is usually mild. The average temperature is of 11.7 °C (53 °F), with a minimum of 5.6 °C (42 °F) and a maximum of 17.8 °C (64.1 °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 30 mm (1.2 in), distributed over 5 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 50% 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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In July, the coldest month of the year, the weather in Rosario is usually mild. The average temperature is of 10.9 °C (52 °F), with a minimum of 4.4 °C (40 °F) and a maximum of 17.3 °C (63.2 °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 25 mm (1 in), distributed over 4 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 52% 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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In August, the weather in Rosario is usually mild. However, there are remarkable differences between night and day. The average temperature is of 12.9 °C (55 °F), with a minimum of 5.8 °C (42.5 °F) and a maximum of 20.1 °C (68.1 °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 30 mm (1.2 in), distributed over 4 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 59% of the time.
The average humidity is 69%.
The average wind speed is 13 kph (8 mph).

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In September, the weather in Rosario is usually very mild. However, there are remarkable differences between night and day. The average temperature is of 15.5 °C (60 °F), with a minimum of 8.6 °C (47.5 °F) and a maximum of 22.5 °C (72.5 °F).
On the coldest nights, which normally occur at the end 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 beginning 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 45 mm (1.8 in), distributed over 5 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 56% of the time.
The average humidity is 65%.
The average wind speed is 15 kph (9 mph).

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In October, the weather in Rosario is usually warm. The average temperature is of 18.7 °C (66 °F), with a minimum of 12.2 °C (54 °F) and a maximum of 25.2 °C (77.4 °F).
On the coldest nights, which normally occur at the end 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 beginning 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 110 mm (4.3 in), distributed over 9 days.
The day lasts on average 13 hours and 0 minutes.
There are on average 7.5 hours of sunshine per day. So, the sun shines 58% of the time.
The average humidity is 67%.
The average wind speed is 15 kph (10 mph).

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In November, the weather in Rosario is usually warm. However, there are remarkable differences between night and day. The average temperature is of 21.5 °C (71 °F), with a minimum of 14.9 °C (58.7 °F) and a maximum of 28.2 °C (82.8 °F).
On the coldest nights, which normally occur at the end 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 beginning 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 110 mm (4.3 in), distributed over 9 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 65% of the time.
The average humidity is 63%.
The average wind speed is 15 kph (9 mph).

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In December, the weather in Rosario is usually warm to hot. However, there are remarkable differences between night and day. The average temperature is of 24.0 °C (75 °F), with a minimum of 17.4 °C (63.2 °F) and a maximum of 30.7 °C (87.3 °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 120 mm (4.7 in), distributed over 9 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 66% of the time.
The average humidity is 63%.
The average wind speed is 13 kph (8 mph).