Climate - San Juan (Argentina)

The climate of San Juan is arid subtropical, affected by altitude, with dry, mild winters (but during which it can get cold at night), and very hot, sunny summers.
The city is located in north-central Argentina, at 31 degrees south latitude, and 650 meters (2,130 feet) above sea level.
Due to its location in a valley, with the Andes to the west and mountains to the north-east that exceed 3,000 meters (9,800 feet), the climate is particularly arid. However, thunderstorms can sometimes break out in the summer.
The sun often shines all year round.
Despite the altitude, in summer, from December to February, there can be heat waves.
Since winter is dry, snow in San Juan is rare, however, light snowfalls may occur from time to time, such as in July 2007 and in July 2010. On the other hand, night frosts are quite frequent.
In winter, the difference in temperature between night and day is often noticeable. The wind that comes down from the mountains, called Zonda and similar to the Föhn and the Chinook, is able to raise the temperature by several degrees, it is no coincidence that the heat records exceed 30 °C (86 °F) even in winter.

The average temperature of the coldest month (July) is of 8.5 °C (47.4 °F), that of the warmest month (January) is of 27.9 °C (82.1 °F). Here are the average temperatures.
Precipitation amounts to 90 millimeters (3.5 inches) per year: it is therefore at a desert level. It ranges from 2 mm (0.1 in) in the driest month (June) to 20 mm (0.8 in) in the wettest one (February). Here is the average precipitation.
On average, there are around 3365 sunshine hours per year. Here are the average sunshine hours per day.

San Juan - Weather by month

Based on the period 1991-2020
(January - February - March - April - May - June - July - August - September - October - November - December)

In January, the warmest month of the year, the average temperature is of 27.9 °C (82 °F), with a minimum of 19.7 °C (67.5 °F) and a maximum of 36 °C (96.8 °F).
On the coldest nights of the month, the temperature usually drops to around 13.5 °C (56 °F). However, in January 2019, it dropped to 9 °C (48.2 °F).
On the warmest days of the month, the temperature usually reaches around 41.5 °C (106.5 °F). However, in January 2003, it reached 45.4 °C (113.7 °F).
Precipitation amounts to 15 mm (0.6 in), distributed over 4 days.
On average, there are 340 hours of sunshine per month, i.e. 11 hours per day.
The average humidity is 40%.
The average wind speed is 16 kph (10 kph).

In February, the average temperature is of 26.3 °C (79 °F), with a minimum of 18.4 °C (65.1 °F) and a maximum of 34.1 °C (93.5 °F).
On the coldest nights of the month, the temperature usually drops to around 12 °C (53.5 °F). However, in February 2003, it dropped to 8.1 °C (46.6 °F).
On the warmest days of the month, the temperature usually reaches around 40 °C (103.5 °F). However, in February 2001, it reached 44.6 °C (112.3 °F).
Precipitation amounts to 20 mm (0.8 in), distributed over 3 days.
On average, there are 295 hours of sunshine per month, i.e. 10.5 hours per day.
The average humidity is 44%.
The average wind speed is 15 kph (9 kph).

In March, the average temperature is of 23.8 °C (75 °F), with a minimum of 16.1 °C (60.9 °F) and a maximum of 31.5 °C (88.6 °F).
On the coldest nights of the month, the temperature usually drops to around 9.5 °C (49 °F). However, in March 1995, it dropped to 5.6 °C (42.1 °F).
On the warmest days of the month, the temperature usually reaches around 37.5 °C (99.5 °F). However, in March 2002, it reached 42.1 °C (107.8 °F).
Precipitation amounts to 11 mm (0.4 in), distributed over 2 days.
On average, there are 280 hours of sunshine per month, i.e. 9 hours per day.
The average humidity is 49%.
The average wind speed is 13 kph (8 kph).

In April, the average temperature is of 18.5 °C (65 °F), with a minimum of 10.8 °C (51.4 °F) and a maximum of 26.2 °C (79.1 °F).
On the coldest nights of the month, the temperature usually drops to around 4 °C (39.5 °F). However, in April 2012, it dropped to -1.6 °C (29.1 °F).
On the warmest days of the month, the temperature usually reaches around 32.5 °C (91 °F). However, in April 2002, it reached 39.3 °C (102.7 °F).
Precipitation amounts to only 4 mm (0.2 in), distributed over 1 days.
On average, there are 275 hours of sunshine per month, i.e. 9 hours per day.
The average humidity is 53%.
The average wind speed is 12 kph (7 kph).

In May, the average temperature is of 13.4 °C (56 °F), with a minimum of 5.5 °C (42 °F) and a maximum of 21.2 °C (70.1 °F).
On the coldest nights of the month, the temperature usually drops to around -0.5 °C (31 °F). However, in May 1993, it dropped to -4.1 °C (24.6 °F).
On the warmest days of the month, the temperature usually reaches around 28 °C (83 °F). However, in May 1997, it reached 37.4 °C (99.3 °F).
Precipitation amounts to only 4 mm (0.2 in), distributed over 1 days.
On average, there are 230 hours of sunshine per month, i.e. 7.5 hours per day.
The average humidity is 58%.
The average wind speed is 9 kph (6 kph).

In June, the average temperature is of 9.4 °C (49 °F), with a minimum of 0.9 °C (33.6 °F) and a maximum of 17.9 °C (64.2 °F).
On the coldest nights of the month, the temperature usually drops to around -4.5 °C (24 °F). However, in June 2011, it dropped to -7.5 °C (18.5 °F).
On the warmest days of the month, the temperature usually reaches around 26.5 °C (79.5 °F). However, in June 2015, it reached 35 °C (95 °F).
Precipitation amounts to only 2 mm (0.1 in), distributed over 0 days.
On average, there are 205 hours of sunshine per month, i.e. 7 hours per day.
The average humidity is 55%.
The average wind speed is 10 kph (6 kph).

In July, the coldest month of the year, the average temperature is of 8.5 °C (47 °F), with a minimum of -0.3 °C (31.4 °F) and a maximum of 17.4 °C (63.3 °F).
On the coldest nights of the month, the temperature usually drops to around -5.5 °C (22 °F). However, in July 2011, it dropped to -9 °C (15.8 °F).
On the warmest days of the month, the temperature usually reaches around 26 °C (79 °F). However, in July 2006, it reached 33.4 °C (92.1 °F).
Precipitation amounts to only 4 mm (0.2 in), distributed over 1 days.
On average, there are 240 hours of sunshine per month, i.e. 7.5 hours per day.
The average humidity is 50%.
The average wind speed is 10 kph (6 kph).

In August, the average temperature is of 11.6 °C (53 °F), with a minimum of 2.3 °C (36.1 °F) and a maximum of 21 °C (69.9 °F).
On the coldest nights of the month, the temperature usually drops to around -3.5 °C (25.5 °F). However, in August 1991, it dropped to -7.2 °C (19 °F).
On the warmest days of the month, the temperature usually reaches around 31 °C (87.5 °F). However, in August 2015, it reached 38.5 °C (101.3 °F).
Precipitation amounts to only 3 mm (0.1 in), distributed over 1 days.
On average, there are 255 hours of sunshine per month, i.e. 8 hours per day.
The average humidity is 40%.
The average wind speed is 12 kph (7 kph).

In September, the average temperature is of 15.6 °C (60 °F), with a minimum of 6.5 °C (43.8 °F) and a maximum of 24.7 °C (76.5 °F).
On the coldest nights of the month, the temperature usually drops to around -0.5 °C (31 °F). However, in September 2013, it dropped to -4.1 °C (24.6 °F).
On the warmest days of the month, the temperature usually reaches around 34 °C (93.5 °F). However, in September 2013, it reached 40.8 °C (105.4 °F).
Precipitation amounts to only 6 mm (0.2 in), distributed over 2 days.
On average, there are 265 hours of sunshine per month, i.e. 9 hours per day.
The average humidity is 36%.
The average wind speed is 14 kph (9 kph).

In October, the average temperature is of 20.2 °C (68 °F), with a minimum of 11.3 °C (52.4 °F) and a maximum of 29 °C (84.3 °F).
On the coldest nights of the month, the temperature usually drops to around 4 °C (39 °F). However, in October 1991, it dropped to 1 °C (33.8 °F).
On the warmest days of the month, the temperature usually reaches around 37 °C (99 °F). However, in October 2009, it reached 42.5 °C (108.5 °F).
Precipitation amounts to only 4 mm (0.2 in), distributed over 1 days.
On average, there are 305 hours of sunshine per month, i.e. 10 hours per day.
The average humidity is 36%.
The average wind speed is 16 kph (10 kph).

In November, the average temperature is of 23.8 °C (75 °F), with a minimum of 14.9 °C (58.9 °F) and a maximum of 32.6 °C (90.7 °F).
On the coldest nights of the month, the temperature usually drops to around 7.5 °C (45 °F). However, in November 2014, it dropped to 2.5 °C (36.5 °F).
On the warmest days of the month, the temperature usually reaches around 39.5 °C (103 °F). However, in November 2009, it reached 44.5 °C (112.1 °F).
Precipitation amounts to only 7 mm (0.3 in), distributed over 2 days.
On average, there are 325 hours of sunshine per month, i.e. 11 hours per day.
The average humidity is 35%.
The average wind speed is 17 kph (11 kph).

In December, the average temperature is of 26.6 °C (80 °F), with a minimum of 18 °C (64.4 °F) and a maximum of 35.2 °C (95.3 °F).
On the coldest nights of the month, the temperature usually drops to around 10.5 °C (51 °F). However, in December 2014, it dropped to 6 °C (42.8 °F).
On the warmest days of the month, the temperature usually reaches around 41.5 °C (106.5 °F). However, in December 1995, it reached 45.7 °C (114.3 °F).
Precipitation amounts to 12 mm (0.5 in), distributed over 2 days.
On average, there are 350 hours of sunshine per month, i.e. 11.5 hours per day.
The average humidity is 36%.
The average wind speed is 17 kph (11 kph).