Annual mean 21°C · wettest around April · prevailing wind SE
Warmest
34.8 °C
Coldest
14.2 °C
Wettest
28%
Windiest
5.3 m/s
Prevailing
SE
4.3 m/s average
When this place is good five ratings · thirty-six ten-day sections · click a cell to read it
never good
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Every reading
bars actual · line feels-like, °Cchance of rain, %wind speed, m/ssky covered, %
The average temperature in San Marcos over the whole year is 21°C. August is the hottest month, with highs of about 34°C; January is the coldest, with lows of about 7°C. San Marcos has no sharply defined rainy season: the chance of rain on a given day runs from 19% in July, the driest month, to 21% in April, the wettest. Winds in San Marcos are highest in March, averaging 3.9 m/s (14 km/h), and lightest in September, at 2.6 m/s (9 km/h). The prevailing wind is from the SE. The clearest skies in San Marcos come in August, when the sky is typically 33% covered; May is the cloudiest month, at 54%.
Month by month San Marcos climate by month: average temperatures year round · click a month to read it
Month
High
Low
Feels like
Chance of rain
Cloud
Wind
Being outside
Sun
Walking
January
15°C
7°C
11°C
21%
45%
3.4 m/s
33
2
67
February
17°C
9°C
13°C
19%
53%
3.8 m/s
48
7
63
March
22°C
13°C
19°C
19%
53%
3.9 m/s
69
20
60
April
25°C
17°C
23°C
21%
53%
3.9 m/s
68
38
40
May
29°C
21°C
29°C
21%
54%
3.7 m/s
33
56
11
June
32°C
24°C
34°C
20%
43%
3.3 m/s
5
37
0
July
34°C
25°C
35°C
19%
37%
3.3 m/s
1
22
0
August
34°C
25°C
36°C
20%
33%
3.0 m/s
2
17
0
September
32°C
22°C
33°C
21%
37%
2.6 m/s
13
41
4
October
27°C
17°C
26°C
20%
39%
2.9 m/s
39
51
25
November
21°C
12°C
19°C
21%
49%
3.0 m/s
59
21
57
December
17°C
9°C
14°C
21%
49%
3.1 m/s
47
6
68
High and low are the warmest and coolest of four readings a day — midnight, 6am, noon and 6pm — so a true overnight low can sit a degree or two under them. Chance of rain, cloud and wind are the day’s average; feels-like and the three ratings (each out of 100: Good from 55, Ideal from 80) are read at midday.
Seasons, and the year in short San Marcos weather by season
Year round, San Marcos has days of about 15°C at their warmest in January, its coolest month, and 34°C in August, its warmest; the coolest hours of the day run from 7°C to 25°C through the year, and the average temperature over the year is 21°C around the clock. Rain is most likely around April and least likely around July. Every figure here is a decade of observations blended into one representative year, so it reads as what this date is usually like, not a forecast for one particular day.
San Marcos weather in winterDecember to February
High 16°CLow 8°CRain 20%
Winter in San Marcos has typical daily highs of about 16°C and lows of about 8°C, with a 20% chance of rain on a given day.
San Marcos weather in springMarch to May
High 25°CLow 17°CRain 21%
Spring in San Marcos has typical daily highs of about 25°C and lows of about 17°C, with a 21% chance of rain on a given day.
San Marcos weather in summerJune to August
High 34°CLow 25°CRain 20%
Summer in San Marcos has typical daily highs of about 34°C and lows of about 25°C, with a 20% chance of rain on a given day.
San Marcos weather in autumnSeptember to November
High 27°CLow 17°CRain 21%
Autumn in San Marcos has typical daily highs of about 27°C and lows of about 17°C, with a 21% chance of rain on a given day.
When is the rainy season in San Marcos?
San Marcos has no sharply defined rainy season: the chance of rain on a given day runs from 19% in July, the driest month, to 21% in April, the wettest.
What time of year is San Marcos windiest?
Winds in San Marcos are highest in March, averaging 3.9 m/s (14 km/h), and lightest in September, at 2.6 m/s (9 km/h). The prevailing wind is from the SE.
What is the average temperature in San Marcos year round?
The average temperature in San Marcos over the whole year is 21°C. August is the hottest month, with highs of about 34°C; January is the coldest, with lows of about 7°C.