San Marcos (CA) Weather & Climate: Best Time to Visit
Average temperatures, rainfall, sunshine and the best time to visit San Marcos.
Climate overview of San Marcos
San Marcos, California, United States of America, has a moderate seasonal temperature range, with August reaching 30°C (86°F) and December cooling to 19°C (66°F).
Rainfall is modest, totalling around 309 mm (12 in) annually. The city experiences a distinct dry season from March to November, with warm summers and pleasant winters. December tends to be the wettest month. The most sunshine falls in July, with an average of 10.1 hours of daily sunshine.
San Marcos Weather by Month
Pick a month to see the average temperature, rainfall and sunshine in San Marcos - and find the best time to visit.
Monthly Temperature in San Marcos
In San Marcos, seasonal changes bring about a moderate variation in temperatures. Average maximum daytime temperatures range from a comfortable 30°C (86°F) in August, the warmest time of the year, to a pleasant 19°C (66°F) during cooler months like December.
At night, you can expect temperatures ranging from 17°C (63°F) in August to around 7°C (45°F) during December.
Check out our detailed temperature page for more information.
Temperature ranges by month
Rainfall in San Marcos
San Marcos typically sees modest rainfall throughout the year, with an average annual precipitation of 309 mm (12 in). Significant seasonal changes in precipitation occur throughout the year. In the wettest month, December it receives moderate rainfall, averaging 79 mm (3.1 in) of precipitation, recorded across 8 rainy days. In contrast, the driest month June brings less rainfall, with 0.6 mm (0.02 in) over a single rainy day. For more details, please visit our San Marcos Precipitation page.
The mean monthly precipitation over the year, including rain, hail, and snow
The average number of days each month with precipitation
Sunshine Hours in San Marcos
While the amount of sunshine in San Marcos varies throughout the year, all seasons offer their own charm. Enjoy up to 10.1 hours of daily sun in July, and experience slightly darker atmosphere in February, with about 7.7 hours of daily sunlight.
Visit our detailed sunshine hours page for more information.
Monthly hours of sunshine
Daily hours of sunshine
Daily percentage of sunshine
Humidity in San Marcos by Month
The relative humidity is high throughout the year in San Marcos.
The city experiences its highest humidity in July, reaching 75%. In January, the humidity drops to its lowest level at 64%. What does this mean? Read our detailed page on humidity levels for further details.
Relative humidity over the year
Best Time to Visit San Marcos
Monthly ratings reflect general weather comfort, based on daytime temperature and rainfall. Swimming and winter conditions are highlighted separately where relevant.
- Best overall: January, February, March, April, May, June, July, October and November
- Warmest weather: July, August and September
- Most sunshine: July and August
- Fewest rainy days: June, July, August and September
- Seasonal pattern: A distinct dry season from March to November, with warm summers and pleasant winters
Frequently asked questions about the climate in San Marcos
What is the best time to visit San Marcos?
January, February, March, April, May, June, July, October and November typically offer the most optimal weather in San Marcos. In contrast, August, September and December tend to have less optimal conditions. San Marcos has a distinct dry season from March to November, with warm summers and pleasant winters.
What temperatures can I expect in San Marcos?
Daytime highs range from 19°C (66°F) in December to 30°C (86°F) in August. Nighttime lows range from 7°C (45°F) to 17°C (63°F).
How much rain does San Marcos get?
Annual rainfall is around 309 mm (12 in). December is the wettest month with 79 mm (3.1 in), while June is the driest with 0.6 mm (0.02 in).
How sunny is San Marcos?
San Marcos receives around 3,069 hours of sunshine per year. July is the sunniest month with 304 hours, while February is the cloudiest with just 230 hours. Overall, San Marcos enjoys abundant sunshine.
San Marcos 3-Day Forecast
San Marcos on the map
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