Climate - San Antonio (Texas)

The climate of San Antonio is subtropical, with mild winters and very hot, muggy summers.
The city is located in southern Texas, about 200 km (125 mi) away from the Gulf of Mexico.
Winter, from December to February, is mild, but there may be variations in temperature. Even in the middle of winter, there can be hot days, with highs of 25 °C (77 °F) and more. In other circumstances, it can get cold at night, and the temperature can drop below freezing.
Occasionally, there may be real cold waves, which last a few days, during which the temperature can drop to -10 °C (14 °F) or below. The record is -18 °C (0 °F), set in January 1949. After 1980, the lowest values were -14.5 °C (6 °F) in December 1989 and -13 °C (8.5 °F) in February 2021.
Sometimes the dangerous phenomenon of freezing rain can occur.
Snow in San Antonio is rare. Normally you have to wait a few years between a snowfall with a slight accumulation and another. In December 2017, 5 centimeters (2 inches) of snow fell. In February 2021, snow reached 15 cm (6 in), as it had not happened for decades. The record belongs to January 1985 with 33 cm (13 in).
In the summer, from June to September, the combination of high temperature and humidity makes the heat very unpleasant. On the hottest days, it can reach and exceed 40 °C (104 °F). The record is 44 °C (111 °F), set in early September 2000.
From time to time, the city can be reached by the remnants of a hurricane, coming from the Gulf of Mexico or the Pacific. In general, hurricanes weaken when they penetrate inland, however, they can still bring abundant rains. The hurricane season runs from June to November, although they are more likely from August to October, with a peak in September.
The average temperature of the coldest month (January) is of 11.2 °C (52 °F), that of the warmest month (August) is of 29.7 °C (86 °F). Here are the average temperatures.

Precipitation amounts to 820 millimeters (32.3 inches) per year: so, it is at an intermediate level. The rainiest seasons are spring and autumn, due to the clash of air masses. San Antonio is just outside the "tornado alley", however tornadoes can occasionally occur in the period April-June (and more rarely in autumn). Here is the average precipitation.

On average, there are around 2,630 sunshine hours per year. Here are the average sunshine hours per day.

Best Time

To visit San Antonio, you can choose spring and autumn (in particular, from mid-March to mid-April and from mid-October to mid-November), to avoid the summer heat. In winter, there are long mild periods, but some very cold days cannot be excluded.

Return to the climate of Texas.

San Antonio - Weather by month

Based on the period 1991-2020

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In January, the coldest month of the year, the weather in San Antonio is usually mild. The average temperature is of 11.2 °C (52 °F), with a minimum of 5 °C (41 °F) and a maximum of 17.4 °C (63.3 °F).
On the coldest nights of the month, the temperature usually drops to around -3 °C (26 °F). However, it dropped to -8.9 °C (16 °F) in January 2010.
On the warmest days of the month, the temperature usually reaches around 27 °C (80 °F). However, it reached 30 °C (86 °F) in January 2006.
Precipitation amounts to 50 mm (2 in), distributed over 7 days.
The day lasts on average 10 hours and 30 minutes.
There are on average 5 hours of sunshine per day. So, the sun shines 49% of the time.
The average humidity is 63%.
The average wind speed is 12 kph (8 mph).

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In February, the weather in San Antonio is usually mild. The average temperature is of 13.5 °C (56 °F), with a minimum of 7.3 °C (45.1 °F) and a maximum of 19.7 °C (67.5 °F).
On the coldest nights of the month, the temperature usually drops to around -1.5 °C (29 °F). However, it dropped to -8.3 °C (17.1 °F) in February 2002.
On the warmest days of the month, the temperature usually reaches around 29.5 °C (85 °F). However, it reached 37.8 °C (100 °F) in February 1996.
Precipitation amounts to 45 mm (1.8 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 54% of the time.
The average humidity is 63%.
The average wind speed is 13 kph (8 mph).

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In March, the weather in San Antonio is usually very mild. The average temperature is of 17.1 °C (63 °F), with a minimum of 11 °C (51.8 °F) and a maximum of 23.2 °C (73.8 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 1 °C (34 °F). However, it dropped to -7.2 °C (19 °F) in March 2002.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 31.5 °C (89 °F). However, it reached 37.2 °C (99 °F) in March 1991.
Precipitation amounts to 60 mm (2.4 in), distributed over 8 days.
The day lasts on average 12 hours and 0 minutes.
There are on average 7 hours of sunshine per day. So, the sun shines 58% of the time.
The average humidity is 64%.
The average wind speed is 14 kph (9 mph).

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In April, the weather in San Antonio is usually warm. The average temperature is of 20.8 °C (69 °F), with a minimum of 14.7 °C (58.4 °F) and a maximum of 26.8 °C (80.3 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 5.5 °C (41.5 °F). However, it dropped to 1.7 °C (35.1 °F) in April 1996.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 33.5 °C (92 °F). However, it reached 38.3 °C (100.9 °F) in April 1996.
Precipitation amounts to 60 mm (2.4 in), distributed over 6 days.
The day lasts on average 12 hours and 55 minutes.
There are on average 7 hours of sunshine per day. So, the sun shines 54% of the time.
The average humidity is 64%.
The average wind speed is 15 kph (9 mph).

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In May, the weather in San Antonio is usually warm to hot. The average temperature is of 24.7 °C (76 °F), with a minimum of 19.1 °C (66.4 °F) and a maximum of 30.3 °C (86.6 °F).
On the coldest nights, which normally occur at the beginning of the month, the temperature usually drops to around 11.5 °C (53 °F). However, it dropped to 5.6 °C (42.1 °F) in May 2013.
On the warmest days, which normally occur at the end of the month, the temperature usually reaches around 35.5 °C (96 °F). However, it reached 40 °C (104 °F) in May 2004.
Precipitation amounts to 110 mm (4.3 in), distributed over 8 days.
The day lasts on average 13 hours and 40 minutes.
There are on average 7 hours of sunshine per day. So, the sun shines 52% of the time.
The average humidity is 68%.
The average wind speed is 16 kph (10 mph).

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In June, the weather in San Antonio is usually very hot. The average temperature is of 28.1 °C (83 °F), with a minimum of 22.6 °C (72.7 °F) and a maximum of 33.6 °C (92.4 °F).
On the coldest nights, the temperature usually drops to around 18.5 °C (65 °F). However, it dropped to 14.4 °C (57.9 °F) in June 1995.
On the warmest days, the temperature usually reaches around 37.5 °C (99 °F). However, it reached 42.2 °C (108 °F) in June 2013.
Precipitation amounts to 85 mm (3.3 in), distributed over 7 days.
The day lasts on average 14 hours and 0 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 66% of the time.
The average humidity is 66%.
The average wind speed is 15 kph (9 mph).

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In July, the weather in San Antonio is usually very hot. The average temperature is of 29.3 °C (85 °F), with a minimum of 23.7 °C (74.7 °F) and a maximum of 34.9 °C (94.9 °F).
On the coldest nights of the month, the temperature usually drops to around 21 °C (70 °F). However, it dropped to 17.8 °C (64 °F) in July 2019.
On the warmest days of the month, the temperature usually reaches around 38 °C (100.5 °F). However, it reached 41.7 °C (107.1 °F) in July 2020.
Precipitation amounts to 60 mm (2.4 in), distributed over 5 days.
The day lasts on average 13 hours and 50 minutes.
There are on average 10 hours of sunshine per day. So, the sun shines 72% of the time.
The average humidity is 63%.
The average wind speed is 14 kph (9 mph).

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In August, the warmest month of the year, the weather in San Antonio is usually very hot. The average temperature is of 29.7 °C (85 °F), with a minimum of 23.8 °C (74.9 °F) and a maximum of 35.6 °C (96 °F).
On the coldest nights of the month, the temperature usually drops to around 21 °C (69.5 °F). However, it dropped to 16.1 °C (61 °F) in August 1992.
On the warmest days of the month, the temperature usually reaches around 39 °C (102 °F). However, it reached 43.3 °C (109.9 °F) in August 2011.
Precipitation amounts to 55 mm (2.2 in), distributed over 5 days.
The day lasts on average 13 hours and 5 minutes.
There are on average 9.5 hours of sunshine per day. So, the sun shines 72% of the time.
The average humidity is 60%.
The average wind speed is 13 kph (8 mph).

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In September, the weather in San Antonio is usually warm to hot. The average temperature is of 26.6 °C (80 °F), with a minimum of 20.9 °C (69.6 °F) and a maximum of 32.3 °C (90.1 °F).
On the coldest nights, the temperature usually drops to around 14 °C (57.5 °F). However, it dropped to 8.9 °C (48 °F) in September 2000.
On the warmest days, the temperature usually reaches around 37 °C (98.5 °F). However, it reached 43.9 °C (111 °F) in September 2000.
Precipitation amounts to 100 mm (3.9 in), distributed over 7 days.
The day lasts on average 12 hours and 20 minutes.
There are on average 8 hours of sunshine per day. So, the sun shines 63% of the time.
The average humidity is 64%.
The average wind speed is 12 kph (7 mph).

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In October, the weather in San Antonio is usually warm. The average temperature is of 21.8 °C (71 °F), with a minimum of 15.8 °C (60.4 °F) and a maximum of 27.9 °C (82.2 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 5.5 °C (42 °F). However, it dropped to -2.8 °C (27 °F) in October 1993.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 34 °C (93 °F). However, it reached 37.2 °C (99 °F) in October 1991.
Precipitation amounts to 95 mm (3.7 in), distributed over 6 days.
The day lasts on average 11 hours and 25 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 12 kph (8 mph).

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In November, the weather in San Antonio is usually very mild. The average temperature is of 16.0 °C (61 °F), with a minimum of 9.9 °C (49.8 °F) and a maximum of 22.1 °C (71.7 °F).
On the coldest nights, which normally occur at the end of the month, the temperature usually drops to around 0.5 °C (32.5 °F). However, it dropped to -5 °C (23 °F) in November 1993.
On the warmest days, which normally occur at the beginning of the month, the temperature usually reaches around 29.5 °C (85.5 °F). However, it reached 32.8 °C (91 °F) in November 2017.
Precipitation amounts to 55 mm (2.2 in), distributed over 6 days.
The day lasts on average 10 hours and 40 minutes.
There are on average 5.5 hours of sunshine per day. So, the sun shines 54% of the time.
The average humidity is 66%.
The average wind speed is 12 kph (7 mph).

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In December, the weather in San Antonio is usually mild. The average temperature is of 12.0 °C (54 °F), with a minimum of 5.8 °C (42.4 °F) and a maximum of 18.2 °C (64.7 °F).
On the coldest nights of the month, the temperature usually drops to around -2.5 °C (27.5 °F). However, it dropped to -7.2 °C (19 °F) in December 1996.
On the warmest days of the month, the temperature usually reaches around 27 °C (80.5 °F). However, it reached 30 °C (86 °F) in December 2007.
Precipitation amounts to 50 mm (2 in), distributed over 7 days.
The day lasts on average 10 hours and 20 minutes. December 21, the winter solstice, is the shortest day of the year in the Northern Hemisphere.
There are on average 5 hours of sunshine per day. So, the sun shines 47% of the time.
The average humidity is 64%.
The average wind speed is 12 kph (7 mph).