Weather and climate in La Rioja (Argentina)

The climate of La Rioja is subtropical semi-arid (according to the Köppen classification, semi-arid hot climate - BSh), with dry, mild winters (but during which it can get cold at night), and very hot, quite rainy summers. In summer, the rains often occur in the form of thunderstorms.
The city (formerly known as "Ciudad de Todos los Santos de Nueva Rioja"), capital of the province of La Rioja, is located in northern Argentina, at 29 degrees south latitude, at 500 meters above sea level, and at the foot of the Andes.
In particular, the Sierra de Velasco, in turn belonging to the Sierras Pampeanas, separates the city of La Rioja from the Chilecito Valley. Even further west, about 100 km away, is the closest very high peak, the Nevado de Famatina (or Cerro General Belgrano), 6,115 meters high. In the Andes to the west of La Rioja the climate is semi-arid, however, in summer there can be some rain (and snow in the high mountains).



In winter, from mid-May to mid-August, the difference in temperature between night and day is often significant. In addition, although the winter is mild, there can sometimes be outbreaks of cold air from the south, during which the temperature can drop below freezing at night. This usually happens from late May to early September. The absolute record is -7.2 °C (19 °F), recorded in August 1966, while after 1991, the temperature dropped to -6.5 °C (20.3 °F) in July 2000.
Snow in La Rioja is very rare, both because the winter is dry and because the sun usually warms the ground and raises the temperature a lot during the day. However, on July 16 and 17, 2010, there was a snowfall that produced a light layer, and on the second day the maximum temperature was only 3 °C (37.5 °F).
Summer, from December to February, is very hot, in fact La Rioja is one of the few Argentine cities where the average maximum in December and January exceeds 35 °C (95 °F). Although it is the rainiest season, in no month does it exceed 100 millimeters (4 inches) on average.
During the day it can get hot all year round, in fact, the heat records exceed 30 °C (86 °F) even in winter.
Especially in spring and summer, there can be heat waves, during which the temperature can reach and exceed 40 °C (104 °F). In the worst moments the temperature can reach 45 °C (113 °F). The record is 46.4 °C, set in late December 1971. In December 1995, the temperature reached 46 °C, while in December 2013 the average maximum was 39 °C.

Best Time

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It is difficult to find the best time to visit La Rioja, since the summer is very hot, while in winter there can be sudden changes in temperature, and at night there can be quite intense frosts. You can then choose the period from mid-April to mid-May, in autumn, when the temperature is halfway between winter and summer. In spring it can get very hot.

La Rioja - Climate data

The average temperature of the coldest month (July) is of 11.8 °C (53.3 °F), that of the warmest month (January) is of 28.4 °C (83.0 °F). Here are the average temperatures.
Precipitation amounts to 410 millimeters (16.1 inches) per year: it is therefore quite scarce. It ranges from 3 mm (0.1 in) in the driest month (August) to 90 mm (3.5 in) in the wettest one (January). Here is the average precipitation.
There are on average around 2570 sunshine hours per year. Here are the average hours of sunshine per day.

La Rioja - Weather by month

Based on the period 1991-2020

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January, the hottest month of the year, is generally a very hot month. However, there are remarkable differences between night and day. The average temperature is of 28.4 °C (83 °F), with a minimum of 21.5 °C (70.7 °F) and a maximum of 35.2 °C (95.4 °F).
On the coldest nights of the month, the temperature usually drops to around 15.5 °C (60 °F). However, it dropped to 11.8 °C (53.2 °F) in January 1996.
On the warmest days of the month, the temperature usually reaches around 42 °C (107.5 °F). However, it reached 45.5 °C (113.9 °F) in January 2017.
Precipitation amounts to 90 mm (3.5 in), distributed over 7 days.
The day lasts on average 13 hours and 50 minutes.
There are on average 7.5 hours of sunshine per day. So, the sun shines 54% of the time.
The average humidity is 56%.
The average wind speed is 9 kph (5 mph).

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February is generally a warm to hot month. However, there are remarkable differences between night and day. The average temperature is of 26.6 °C (80 °F), with a minimum of 20.1 °C (68.2 °F) and a maximum of 33.2 °C (91.8 °F).
On the coldest nights of the month, the temperature usually drops to around 14 °C (57.5 °F). However, it dropped to 9.5 °C (49.1 °F) in February 1993.
On the warmest days of the month, the temperature usually reaches around 40 °C (104 °F). However, it reached 44.1 °C (111.4 °F) in February 2003.
Precipitation amounts to 79 mm (3.1 in), distributed over 7 days.
The day lasts on average 13 hours and 5 minutes.
There are on average 7.5 hours of sunshine per day. So, the sun shines 56% of the time.
The average humidity is 60%.
The average wind speed is 8 kph (5 mph).

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March is generally a warm to hot month. The average temperature is of 24.7 °C (76 °F), with a minimum of 18.6 °C (65.5 °F) and a maximum of 30.8 °C (87.4 °F).
On the coldest nights, the temperature usually drops to around 12.5 °C (55 °F). However, it dropped to 9 °C (48.2 °F) in March 2011.
On the warmest days, the temperature usually reaches around 37.5 °C (99.5 °F). However, it reached 42 °C (107.6 °F) in March 2002.
Precipitation amounts to 63 mm (2.5 in), distributed over 5 days.
The day lasts on average 12 hours and 10 minutes.
There are on average 6.5 hours of sunshine per day. So, the sun shines 54% of the time.
The average humidity is 64%.
The average wind speed is 8 kph (5 mph).

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April is generally a warm month. The average temperature is of 20.7 °C (69 °F), with a minimum of 14.6 °C (58.3 °F) and a maximum of 26.8 °C (80.2 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 7.5 °C (45 °F). However, it dropped to 2 °C (35.6 °F) in April 2007.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 33.5 °C (92 °F). However, it reached 38.6 °C (101.5 °F) in April 1995.
Precipitation amounts to 31 mm (1.2 in), distributed over 3 days.
The day lasts on average 11 hours and 25 minutes.
There are on average 6.5 hours of sunshine per day. So, the sun shines 55% of the time.
The average humidity is 66%.
The average wind speed is 7 kph (4 mph).

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May is generally a very mild month. The average temperature is of 16.2 °C (61 °F), with a minimum of 9.9 °C (49.8 °F) and a maximum of 22.6 °C (72.7 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 2.5 °C (36.5 °F). However, it dropped to -3 °C (26.6 °F) in May 2008.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 30 °C (86 °F). However, it reached 37.3 °C (99.1 °F) in May 1997.
Precipitation amounts to only 8 mm (0.3 in), distributed over 2 days.
The day lasts on average 10 hours and 35 minutes.
There are on average 6 hours of sunshine per day. So, the sun shines 55% of the time.
The average humidity is 67%.
The average wind speed is 6 kph (4 mph).

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June is generally a mild month. However, there are remarkable differences between night and day. The average temperature is of 12.6 °C (55 °F), with a minimum of 5.6 °C (42.1 °F) and a maximum of 19.7 °C (67.5 °F).
On the coldest nights, the temperature usually drops to around -0.5 °C (31 °F). However, it dropped to -4 °C (24.8 °F) in June 2011.
On the warmest days, the temperature usually reaches around 25.5 °C (78 °F). However, it reached 29.4 °C (84.9 °F) in June 2001.
Precipitation amounts to only 4 mm (0.2 in), and all occurs in one day.
The day lasts on average 10 hours and 20 minutes. June 21, the winter solstice, is the shortest day of the year in the Southern Hemisphere.
There are on average 6 hours of sunshine per day. So, the sun shines 56% of the time.
The average humidity is 66%.
The average wind speed is 6 kph (4 mph).

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July, the coldest month of the year, is generally a mild month. However, there are remarkable differences between night and day. The average temperature is of 11.8 °C (53 °F), with a minimum of 4.2 °C (39.6 °F) and a maximum of 19.5 °C (67.1 °F).
On the coldest nights of the month, the temperature usually drops to around -2 °C (28.5 °F). However, it dropped to -6.5 °C (20.3 °F) in July 2000.
On the warmest days of the month, the temperature usually reaches around 27 °C (81 °F). However, it reached 34 °C (93.2 °F) in July 1997.
Precipitation amounts to only 4 mm (0.2 in), and all occurs in one day.
The day lasts on average 10 hours and 30 minutes.
There are on average 7 hours of sunshine per day. So, the sun shines 65% of the time.
The average humidity is 58%.
The average wind speed is 7 kph (4 mph).

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August is generally a very mild month. However, there are remarkable differences between night and day. The average temperature is of 15.1 °C (59 °F), with a minimum of 6.9 °C (44.4 °F) and a maximum of 23.3 °C (73.9 °F).
On the coldest nights of the month, the temperature usually drops to around 0 °C (32 °F). However, it dropped to -2.9 °C (26.8 °F) in August 2020.
On the warmest days of the month, the temperature usually reaches around 33 °C (91.5 °F). However, it reached 40 °C (104 °F) in August 1996.
Precipitation amounts to only 3 mm (0.1 in), distributed over 0 days.
The day lasts on average 11 hours and 5 minutes.
There are on average 7.5 hours of sunshine per day. So, the sun shines 69% of the time.
The average humidity is 48%.
The average wind speed is 8 kph (5 mph).

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September is generally a warm month. However, there are remarkable differences between night and day. The average temperature is of 19.1 °C (66 °F), with a minimum of 11.3 °C (52.3 °F) and a maximum of 26.9 °C (80.4 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 3 °C (37 °F). However, it dropped to -2.5 °C (27.5 °F) in September 2010.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 36 °C (97 °F). However, it reached 42.6 °C (108.7 °F) in September 2004.
Precipitation amounts to only 9 mm (0.4 in), and all occurs in one day.
The day lasts on average 11 hours and 55 minutes.
There are on average 7.5 hours of sunshine per day. So, the sun shines 61% of the time.
The average humidity is 44%.
The average wind speed is 9 kph (5 mph).

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October is generally a warm to hot month. However, there are remarkable differences between night and day. The average temperature is of 23.4 °C (74 °F), with a minimum of 15.9 °C (60.6 °F) and a maximum of 30.8 °C (87.4 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 8 °C (46 °F). However, it dropped to 4.2 °C (39.6 °F) in October 1991.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 39.5 °C (103.5 °F). However, it reached 45.2 °C (113.4 °F) in October 2009.
Precipitation amounts to 20 mm (0.8 in), distributed over 2 days.
The day lasts on average 12 hours and 50 minutes.
There are on average 8 hours of sunshine per day. So, the sun shines 62% of the time.
The average humidity is 46%.
The average wind speed is 10 kph (6 mph).

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November is generally a warm to hot month. However, there are remarkable differences between night and day. The average temperature is of 26.2 °C (79 °F), with a minimum of 18.9 °C (66 °F) and a maximum of 33.6 °C (92.5 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 11 °C (52 °F). However, it dropped to 6.5 °C (43.7 °F) in November 2010.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 41 °C (106 °F). However, it reached 44.6 °C (112.3 °F) in November 2003.
Precipitation amounts to 32 mm (1.3 in), distributed over 3 days.
The day lasts on average 13 hours and 35 minutes.
There are on average 8 hours of sunshine per day. So, the sun shines 58% of the time.
The average humidity is 48%.
The average wind speed is 10 kph (6 mph).

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December is generally a very hot month. However, there are remarkable differences between night and day. The average temperature is of 28.1 °C (83 °F), with a minimum of 20.8 °C (69.4 °F) and a maximum of 35.4 °C (95.7 °F).
On the coldest nights of the month, the temperature usually drops to around 14.5 °C (58 °F). However, it dropped to 11 °C (51.8 °F) in December 2010.
On the warmest days of the month, the temperature usually reaches around 42.5 °C (108 °F). However, it reached 46 °C (114.8 °F) in December 1995.
Precipitation amounts to 67 mm (2.6 in), distributed over 6 days.
The day lasts on average 14 hours and 0 minutes. December 21, the summer solstice, is the longest day of the year in the Southern Hemisphere.
There are on average 7.5 hours of sunshine per day. So, the sun shines 54% of the time.
The average humidity is 51%.
The average wind speed is 9 kph (6 mph).