See exactly when rain will start and stop with a minute-by-minute precipitation nowcast for the next hour.
Compare today's weather with yesterday's data and track temperature trends over time.
Hourly Forecast
Daylight Hours
05:49
Sunrise
17:46
Sunset
Moon
Waxing Gibbous
16:34
Moonrise
03:54
Moonset
Daily Forecast
Thursday
Today
Saturday
Sunday
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Air Quality Data Available
Upgrade to access real-time air quality data for San Marcos.
UV Index
Humidity
Current stargazing conditions?
See sky darkness, moon phase, and the best viewing window for San Marcos.
View stargazing scoreWeather in San Marcos tomorrow, September 25, 2026
San Marcos starts September 25, 2026 looking damp, with rain in the forecast and wetter spells likely at times. Waterproof kit is the safer call for early plans. Wetter spells lean into the morning, when rain odds reach about 46% near 00:00. Skies look heaviest around 00:00, with cover close to 93%.
Temperatures climb from an overnight low near 21°C toward a daytime high of about 28°C. Relative humidity sits between 63% and 100%, reaching its peak around 02:00. Expect gentle winds, highest near 12:00 at 1.8 km/h.
Through the afternoon wet weather remains a factor, with rain chances near 58% around 13:00. Cloud also stays substantial, close to 96% near 18:00. Expect visibility near 10.0 km, with poorer spells close to 0.1 km. Sunrise is at 05:49 and sunset at 17:45, giving 11 hours 56 minutes of sunlight today.
Taken together, San Marcos looks wet enough on September 25, 2026 that flexible outdoor plans work best, with temperatures peaking near 28°C.
Frequently asked questions about weather in San Marcos
How warm does it get in San Marcos?
The warmest month in San Marcos is March, with average high temperatures of 34°C. The average temperature during this period is around 27°C.
How cold does it get in San Marcos?
The coldest month in San Marcos is January, with average low temperatures of 20°C. The average temperature during this period is around 25°C.
What is the wettest time of year in San Marcos?
The wettest month in San Marcos is June, with an average of 342mm of precipitation.
What is the driest time of year in San Marcos?
The driest month in San Marcos is January, with an average of 2mm of precipitation.
Explore more weather forecasts
- San Salvador, Departamento de San Salvador
- Santo Tomás, Departamento de San Salvador
- Soyapango, Departamento de San Salvador
- Delgado, Departamento de San Salvador
- San Miguel, Departamento de San Miguel
- Mejicanos, Departamento de San Salvador
- Santa Ana, Departamento de Santa Ana
- Cuscatancingo, Departamento de San Salvador
- Santa Tecla, Departamento de La Libertad
- Ayutuxtepeque, Departamento de San Salvador
- Apopa, Departamento de San Salvador
- Ilopango, Departamento de San Salvador
