, mitigated by altitude, with a very mild winter from mid-November to early March, a warm and dry period from March to May, and a warm summer with some rain from June to mid-October.
The city is located in central Mexico, at the 22nd parallel, and at 1,865 meters (6,120 feet) above sea level, and is the capital of the homonymous state.
Although the winter is mild, it gets quite cold at night, and sometimes colder air masses can come down from the United States. In December 1997, it snowed and the temperature dropped to -9 °C (16 °F).
On the hottest days of the year, which generally occur in May and sometimes in April, the temperature can reach or exceed 35 °C (95 °F).
Summer, being not very rainy, is a sunny season.
In theory, San Luis Potosí can be visited all year round, since the summer is not too rainy and the winter is not too cold. However, you can choose the period from November to March, which is the driest season, and it is not hot, as it can sometimes happen in April and May.
. Here are the average temperatures.
January, 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
13.1 °C, with a minimum of
3.6 °C and a maximum of
22.6 °C.

On the coldest nights of the month, the temperature usually drops to around
-2.5 °C. However, it dropped to
-6 °C in January 2006.

On the warmest days of the month, the temperature usually reaches around
27.5 °C. However, it reached
30.1 °C in January 2017.

Precipitation amounts to
15 mm, distributed over 2 days.
The day lasts on average 11 hours and 0 minutes.

There are on average 7 hours of sunshine per day. So, the sun shines 65% of the time.
The average humidity is 55%.
The average wind speed is of
8.4 kph.
February is generally a very mild month. However, there are remarkable differences between night and day. The average temperature is of
15.1 °C, with a minimum of
5.1 °C and a maximum of
25.2 °C.

On the coldest nights of the month, the temperature usually drops to around
-1 °C. However, it dropped to
-5 °C in February 1999.

On the warmest days of the month, the temperature usually reaches around
29.5 °C. However, it reached
35.6 °C in February 2019.

Precipitation amounts to
10 mm, distributed over 2 days.
The day lasts on average 11 hours and 25 minutes.

There are on average 8.5 hours of sunshine per day. So, the sun shines 73% of the time.
The average humidity is 49%.
The average wind speed is of
9.6 kph.
March is generally a very mild month. However, there are remarkable differences between night and day. The average temperature is of
17.4 °C, with a minimum of
7.1 °C and a maximum of
27.6 °C.

On the coldest nights of the month, the temperature usually drops to around
1 °C. However, it dropped to
-5.1 °C in March 1996.

On the warmest days of the month, the temperature usually reaches around
32 °C. However, it reached
34.6 °C in March 2020.

Precipitation amounts to only
5 mm, distributed over 2 days.
The day lasts on average 12 hours and 5 minutes.

There are on average 8.5 hours of sunshine per day. So, the sun shines 72% of the time.
The average humidity is 44%.
The average wind speed is of
10.9 kph.
April is generally a warm month. However, there are remarkable differences between night and day. The average temperature is of
19.8 °C, with a minimum of
9.6 °C and a maximum of
30.1 °C.

On the coldest nights of the month, the temperature usually drops to around
4.5 °C. However, it dropped to
1 °C in April 2000.

On the warmest days of the month, the temperature usually reaches around
34 °C. However, it reached
36.2 °C in April 1998.

Precipitation amounts to
20 mm, distributed over 3 days.
The day lasts on average 12 hours and 40 minutes.

There are on average 8.5 hours of sunshine per day. So, the sun shines 67% of the time.
The average humidity is 41%.
The average wind speed is of
10.8 kph.
May, the warmest month of the year, is generally a warm month. However, there are remarkable differences between night and day. The average temperature is of
21.2 °C, with a minimum of
11.5 °C and a maximum of
30.9 °C.

On the coldest nights of the month, the temperature usually drops to around
7.5 °C. However, it dropped to
3.8 °C in May 2011.

On the warmest days of the month, the temperature usually reaches around
35 °C. However, it reached
38.2 °C in May 2011.

Precipitation amounts to
40 mm, distributed over 6 days.
The day lasts on average 13 hours and 10 minutes.

There are on average 9 hours of sunshine per day. So, the sun shines 69% of the time.
The average humidity is 48%.
The average wind speed is of
9.9 kph.
June is generally a warm month. However, there are remarkable differences between night and day. The average temperature is of
20.9 °C, with a minimum of
12.4 °C and a maximum of
29.3 °C.

On the coldest nights of the month, the temperature usually drops to around
9 °C. However, it dropped to
6.7 °C in June 2011.

On the warmest days of the month, the temperature usually reaches around
34 °C. However, it reached
37.8 °C in June 1995.

Precipitation amounts to
65 mm, distributed over 7 days.
The day lasts on average 13 hours and 30 minutes. June 21, the summer solstice, is the longest day of the year in the Northern Hemisphere.

There are on average 9 hours of sunshine per day. So, the sun shines 65% of the time.
The average humidity is 58%.
The average wind speed is of
10.9 kph.
July is generally a warm month. However, there are remarkable differences between night and day. The average temperature is of
19.8 °C, with a minimum of
12.1 °C and a maximum of
27.6 °C.

On the coldest nights of the month, the temperature usually drops to around
9 °C. However, it dropped to
6 °C in July 2013.

On the warmest days of the month, the temperature usually reaches around
31.5 °C. However, it reached
34.5 °C in July 2009.

Precipitation amounts to
65 mm, distributed over 8 days.
The day lasts on average 13 hours and 20 minutes.

There are on average 9.5 hours of sunshine per day. So, the sun shines 71% of the time.
The average humidity is 63%.
The average wind speed is of
11 kph.
August is generally a warm month. However, there are remarkable differences between night and day. The average temperature is of
19.8 °C, with a minimum of
12 °C and a maximum of
27.7 °C.

On the coldest nights of the month, the temperature usually drops to around
8.5 °C. However, it dropped to
4.2 °C in August 2013.

On the warmest days of the month, the temperature usually reaches around
31 °C. However, it reached
34 °C in August 2011.

Precipitation amounts to
60 mm, distributed over 7 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 63% of the time.
The average humidity is 63%.
The average wind speed is of
11 kph.
September is generally a warm month. However, there are remarkable differences between night and day. The average temperature is of
19.1 °C, with a minimum of
12 °C and a maximum of
26.2 °C.

On the coldest nights of the month, the temperature usually drops to around
7.5 °C. However, it dropped to
3 °C in September 2000.

On the warmest days of the month, the temperature usually reaches around
30.5 °C. However, it reached
33 °C in September 1991.

Precipitation amounts to
65 mm, distributed over 8 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 55% of the time.
The average humidity is 69%.
The average wind speed is of
9.5 kph.
October is generally a very mild month. However, there are remarkable differences between night and day. The average temperature is of
17.4 °C, with a minimum of
9.2 °C and a maximum of
25.7 °C.

On the coldest nights of the month, the temperature usually drops to around
3 °C. However, it dropped to
-3 °C in October 2013.

On the warmest days of the month, the temperature usually reaches around
30 °C. However, it reached
33 °C in October 2009.

Precipitation amounts to
30 mm, distributed over 5 days.
The day lasts on average 11 hours and 35 minutes.

There are on average 7 hours of sunshine per day. So, the sun shines 62% of the time.
The average humidity is 65%.
The average wind speed is of
8 kph.
November is generally a very mild month. However, there are remarkable differences between night and day. The average temperature is of
15.2 °C, with a minimum of
6.2 °C and a maximum of
24.2 °C.

On the coldest nights of the month, the temperature usually drops to around
-0.5 °C. However, it dropped to
-5.4 °C in November 2011.

On the warmest days of the month, the temperature usually reaches around
28.5 °C. However, it reached
30.7 °C in November 2017.

Precipitation amounts to
10 mm, distributed over 2 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 62%.
The average wind speed is of
7.5 kph.
December is generally a mild month. However, there are remarkable differences between night and day. The average temperature is of
13.6 °C, with a minimum of
4 °C and a maximum of
23.2 °C.

On the coldest nights of the month, the temperature usually drops to around
-2.5 °C. However, it dropped to
-9 °C in December 1997.

On the warmest days of the month, the temperature usually reaches around
28 °C. However, it reached
30 °C in December 2011.

Precipitation amounts to
10 mm, distributed over 2 days.
The day lasts on average 10 hours and 50 minutes. December 21, the winter solstice, is the shortest day of the year in the Northern Hemisphere.

There are on average 7 hours of sunshine per day. So, the sun shines 63% of the time.
The average humidity is 56%.
The average wind speed is of
7.7 kph.