Climate and average weather in San Marcos
In San Marcos, the weather is mild, wet, and partly cloudy and remarkably steady, with daytime highs holding near mild levels all year. The wettest stretch peaks around June.
Over the course of the year, the temperature in San Marcos typically varies from 10°C to 21°C, and is rarely below 8°C or above 23°C. April is the hottest month of the year, while December is the coldest.
Based on the travel score, the best times of year to visit San Marcos for warm-weather activities are from early January to mid March and late November to late December.
- Hottest
- Apr
- 21°
- Coldest
- Dec
- 10°
- Wettest
- Jun
- 416 mm
- Driest
- Jan
- 24 mm
- Rain / yr
- 2395 mm
- 258 wet days
- Daylight
- 11.1–12.9 h
- shortest–longest
- Elevation
- 2,380 m
- 15.0°N
- Clearest
- Feb
- 38% cloud
San Marcos weather by month, at a glance
The whole year in one picture — sky, rain, humidity, temperature and travel score. Click any band to jump to its full chart.
Each stripe is one measure across the whole year, stacked so a single day reads top to bottom. The sky band runs overcast grey on top down to clear blue at the base — more blue means sunnier — followed by the rainfall curve, the humidity band, a temperature strip that tints each stretch of the year by how warm its average high is, and the travel-score line at the foot. Scan straight down any date to read that day across every measure at once; the score climbs highest around early January to mid March.
Temperature through the year
Daily average highs and lows in San Marcos, from 1991–2020 of climate data. The shaded bands show the range most days fall in — 10th to 90th percentile.
Temperatures in San Marcos stay fairly even through the year, without a distinct hot or cool season. The warmest month is April, with an average high of 21°C and low of 12°C; the coolest is December, with an average low of 10°C and high of 19°C.
Days typically run about 9°C warmer than nights, with the widest day–night swing (around 11°C) in February.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high (°C) | 20 | 21 | 21 | 21 | 21 | 20 | 20 | 20 | 20 | 20 | 20 | 19 |
| Avg low (°C) | 10 | 10 | 11 | 12 | 13 | 13 | 12 | 12 | 13 | 12 | 11 | 10 |
| Avg high (°C) | Avg low (°C) | |
|---|---|---|
| Jan | 20 | 10 |
| Feb | 21 | 10 |
| Mar | 21 | 11 |
| Apr | 21 | 12 |
| May | 21 | 13 |
| Jun | 20 | 13 |
| Jul | 20 | 12 |
| Aug | 20 | 12 |
| Sep | 20 | 13 |
| Oct | 20 | 12 |
| Nov | 20 | 11 |
| Dec | 19 | 10 |
Average hourly temperature in San Marcos
A compact picture of the whole year, hour by hour: each column is a day, each row an hour, and the color is the modeled average temperature. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.
Read left to right for the day of the year and top to bottom for the hour of the day; the color is the modeled temperature, cool blues through to hot reds on the same scale as the other charts. A vertical slice is a single day's swing — coolest just before dawn, warmest in the mid-afternoon — while a horizontal slice follows one hour across the seasons. The darker overlay marks night and the lighter one the twilight around sunrise and sunset. Colors run warmest on April afternoons, near 21°C, and coldest before dawn in December, near 10°C.
San Marcos weather by month
Every month at a glance. Click a month for its detailed page.
| Month | High / Low (°C) | Rainfall (mm) | Wet days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|
| Jan | 20° / 10° | 24 | 7.4 | 11.2 | 6.9 |
| Feb | 21° / 10° | 25 | 7.9 | 11.5 | 7.0 |
| Mar | 21° / 11° | 64 | 16.7 | 11.9 | 5.8 |
| Apr | 21° / 12° | 124 | 23.8 | 12.3 | 4.5 |
| May | 21° / 13° | 323 | 29.7 | 12.7 | 3.5 |
| Jun | 20° / 13° | 416 | 29.2 | 12.9 | 3.3 |
| Jul | 20° / 12° | 268 | 28.3 | 12.8 | 3.6 |
| Aug | 20° / 12° | 325 | 29.7 | 12.5 | 3.4 |
| Sep | 20° / 13° | 415 | 29.7 | 12.1 | 3.2 |
| Oct | 20° / 12° | 293 | 28.8 | 11.7 | 3.5 |
| Nov | 20° / 11° | 85 | 18 | 11.3 | 5.1 |
| Dec | 19° / 10° | 34 | 8.6 | 11.1 | 6.6 |
Chance of rain
How likely it is to rain on a typical day, and how that shifts across the wetter and drier seasons.
San Marcos gets about 2395 mm of precipitation a year. On a typical day the chance of rain is very wet, but that rises and falls sharply with the seasons.
The wetter season lasts 7.2 months, from around Apr 1 to Nov 5, peaking in September at about 99% chance on a given day. The drier stretch runs the rest of the year, bottoming out around Jan 3.
June is the wettest month by volume, with 416 mm over about 29 wet days; January is the driest, with 24 mm.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rain on a day (%) | 24 | 29 | 54 | 80 | 95 | 97 | 92 | 96 | 99 | 92 | 59 | 29 |
| Rain days | 7 | 8 | 17 | 24 | 30 | 29 | 28 | 30 | 30 | 29 | 18 | 9 |
| Rain on a day (%) | Rain days | |
|---|---|---|
| Jan | 24 | 7 |
| Feb | 29 | 8 |
| Mar | 54 | 17 |
| Apr | 80 | 24 |
| May | 95 | 30 |
| Jun | 97 | 29 |
| Jul | 92 | 28 |
| Aug | 96 | 30 |
| Sep | 99 | 30 |
| Oct | 92 | 29 |
| Nov | 59 | 18 |
| Dec | 29 | 9 |
Monthly rainfall
Over a full year, San Marcos collects about 2395 mm of rain across 258 wet days — roughly 200 mm in an average month.
It doesn’t fall evenly. June is the wettest month with 416 mm, while January is the driest at just 24 mm. The three wettest months alone bring about 48% of the year’s total.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Rainfall (mm) | 24 | 25 | 64 | 124 | 323 | 416 | 268 | 325 | 415 | 293 | 85 | 34 |
| Rain days | 7 | 8 | 17 | 24 | 30 | 29 | 28 | 30 | 30 | 29 | 18 | 9 |
| Rainfall (mm) | Rain days | |
|---|---|---|
| Jan | 24 | 7 |
| Feb | 25 | 8 |
| Mar | 64 | 17 |
| Apr | 124 | 24 |
| May | 323 | 30 |
| Jun | 416 | 29 |
| Jul | 268 | 28 |
| Aug | 325 | 30 |
| Sep | 415 | 30 |
| Oct | 293 | 29 |
| Nov | 85 | 18 |
| Dec | 34 | 9 |
Clouds and sunshine
How often the daytime sky is clear, partly cloudy or overcast.
In San Marcos, the average share of the sky covered by clouds shows significant seasonal variation over the course of the year.
The clearer part of the year begins around November 7 and lasts for 5.5 months, ending around April 22. The clearest month is February, when the sky is clear, mostly clear, or partly cloudy 82% of the time on average.
The cloudier part of the year begins around April 23 and lasts for 6.5 months, ending around November 6. The cloudiest month is September, when it is overcast or mostly cloudy 94% of the time.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Clearer (%) | 81 | 82 | 71 | 48 | 16 | 7 | 13 | 11 | 6 | 16 | 50 | 77 |
| Cloudier (%) | 19 | 18 | 29 | 52 | 84 | 93 | 87 | 89 | 94 | 84 | 50 | 23 |
| Clearer (%) | Cloudier (%) | |
|---|---|---|
| Jan | 81 | 19 |
| Feb | 82 | 18 |
| Mar | 71 | 29 |
| Apr | 48 | 52 |
| May | 16 | 84 |
| Jun | 7 | 93 |
| Jul | 13 | 87 |
| Aug | 11 | 89 |
| Sep | 6 | 94 |
| Oct | 16 | 84 |
| Nov | 50 | 50 |
| Dec | 77 | 23 |
Daylight, sunrise and sunset
Hours of daylight through the year, with sunrise and sunset times.
The gold band is daylight — sunrise runs along its lower edge, sunset along the upper — so it widens toward summer and pinches toward winter, with night the dark area above and below. The longest day, around June 7, brings about 12 h 54 min of light; the shortest, around January 1, only 11 h 06 min — a swing of roughly 1 h 48 min.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Daylight (h) | 11.2 | 11.5 | 11.9 | 12.3 | 12.7 | 12.9 | 12.8 | 12.5 | 12.1 | 11.7 | 11.3 | 11.1 |
| Sunrise (AM) | 6:40 | 6:37 | 6:20 | 5:57 | 5:43 | 5:41 | 5:49 | 5:56 | 5:59 | 6:02 | 6:14 | 6:30 |
| Sunset (PM) | 5:53 | 6:07 | 6:14 | 6:17 | 6:24 | 6:34 | 6:37 | 6:26 | 6:04 | 5:42 | 5:31 | 5:37 |
| Daylight (h) | Sunrise (AM) | Sunset (PM) | |
|---|---|---|---|
| Jan | 11.2 | 6:40 | 5:53 |
| Feb | 11.5 | 6:37 | 6:07 |
| Mar | 11.9 | 6:20 | 6:14 |
| Apr | 12.3 | 5:57 | 6:17 |
| May | 12.7 | 5:43 | 6:24 |
| Jun | 12.9 | 5:41 | 6:34 |
| Jul | 12.8 | 5:49 | 6:37 |
| Aug | 12.5 | 5:56 | 6:26 |
| Sep | 12.1 | 5:59 | 6:04 |
| Oct | 11.7 | 6:02 | 5:42 |
| Nov | 11.3 | 6:14 | 5:31 |
| Dec | 11.1 | 6:30 | 5:37 |
Sunny days
How many genuinely sunny days each month brings — days the sky stays clear or mostly clear — banded into plain-language zones.
San Marcos averages about 6 sunny days a month — counting the days the sky stays clear or mostly clear — with a clear seasonal swing between 0 and 17 days.
The sunnier stretch runs 5.1 months, from around Nov 13 to Apr 17. The sunniest month is February, with roughly 17 sunny days (bright).
The greyest month is September, down near 0 sunny days — about 100% fewer than the February peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Sunny days | 17 | 15 | 13 | 7 | 2 | 0 | 1 | 1 | 0 | 2 | 7 | 14 |
| Sky | Bright | Bright | Mixed | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Gloomy | Mixed |
| Sunny days | Sky | |
|---|---|---|
| Jan | 17 | Bright |
| Feb | 15 | Bright |
| Mar | 13 | Mixed |
| Apr | 7 | Gloomy |
| May | 2 | Gloomy |
| Jun | 0 | Gloomy |
| Jul | 1 | Gloomy |
| Aug | 1 | Gloomy |
| Sep | 0 | Gloomy |
| Oct | 2 | Gloomy |
| Nov | 7 | Gloomy |
| Dec | 14 | Mixed |
Humidity comfort
Share of days at each humidity comfort level, based on the dew point — the measure that tracks how muggy it actually feels.
Humidity comfort is graded by the dew point — the temperature at which the air would be fully saturated — because it tracks how muggy it actually feels far better than relative humidity does. A low dew point feels dry and crisp; a high one feels sticky and oppressive no matter the reading on a humidity gauge.
In San Marcos, the air stays dry or comfortable essentially all year. Even in May, the muggiest month, it feels humid or worse only about 2% of the time — humidity is not something you need to plan around here.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Dry (%) | 100 | 98 | 89 | 68 | 35 | 23 | 53 | 44 | 23 | 38 | 78 | 96 |
| Comfortable (%) | 0 | 2 | 11 | 31 | 64 | 77 | 47 | 56 | 77 | 62 | 22 | 4 |
| Humid (%) | 0 | 0 | 0 | 0 | 2 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Dry (%) | Comfortable (%) | Humid (%) | |
|---|---|---|---|
| Jan | 100 | 0 | 0 |
| Feb | 98 | 2 | 0 |
| Mar | 89 | 11 | 0 |
| Apr | 68 | 31 | 0 |
| May | 35 | 64 | 2 |
| Jun | 23 | 77 | 0 |
| Jul | 53 | 47 | 0 |
| Aug | 44 | 56 | 0 |
| Sep | 23 | 77 | 0 |
| Oct | 38 | 62 | 0 |
| Nov | 78 | 22 | 0 |
| Dec | 96 | 4 | 0 |
Wind
Average wind speed through the year, banded into plain-language speed zones so a number reads as 'breezy' or 'calm' without knowing the scale.
This is the average sustained wind speed at the standard 10 metres above open ground — the steady flow a weather station reports, not the sharper gusts that come and go, which can run half again as fast. It's the number that says whether a place is generally breezy or calm.
Wind in San Marcos is steady company: average speeds sit near 4 km/h — calm — in every month of the year, with no meaningful windy or calm season.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Wind speed (km/h) | 5 | 5 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 4 | 5 | 5 |
| Feels | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm | calm |
| Wind speed (km/h) | Feels | |
|---|---|---|
| Jan | 5 | calm |
| Feb | 5 | calm |
| Mar | 4 | calm |
| Apr | 4 | calm |
| May | 4 | calm |
| Jun | 4 | calm |
| Jul | 4 | calm |
| Aug | 4 | calm |
| Sep | 4 | calm |
| Oct | 4 | calm |
| Nov | 5 | calm |
| Dec | 5 | calm |
Hazard calendar for San Marcos
When the seasonal hazards worth planning around — the rainy season, tropical-cyclone risk and dust haze — are active through the year.
San Marcos's rainy season runs May–October, when most of the year's rain falls.
Best time to visit San Marcos
To characterize how pleasant the weather is in San Marcos throughout the year, we compute two travel scores — one for general sightseeing, one for beach and pool weather.
Around early March, San Marcos is still near the tail of its best-weather window — great conditions with the peak-season crowds already thinning.
Inferred from the travel-score curve; month-by-month visitor numbers are a planned addition.
The travel score favors clear, rainless days with daytime highs between 18°C and 28°C. Based on this score, the best time of year to visit San Marcos for general outdoor tourist activities is from late November to mid March, with a peak score in the first week of February.
The travel score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Travel score (0–10) | 7.0 | 7.0 | 5.8 | 4.5 | 3.5 | 3.3 | 3.5 | 3.4 | 3.2 | 3.5 | 5.1 | 6.6 |
| Rating | good | good | good | fair | fair | poor | fair | poor | poor | fair | fair | good |
| Travel score (0–10) | Rating | |
|---|---|---|
| Jan | 7.0 | good |
| Feb | 7.0 | good |
| Mar | 5.8 | good |
| Apr | 4.5 | fair |
| May | 3.5 | fair |
| Jun | 3.3 | poor |
| Jul | 3.5 | fair |
| Aug | 3.4 | poor |
| Sep | 3.2 | poor |
| Oct | 3.5 | fair |
| Nov | 5.1 | fair |
| Dec | 6.6 | good |
The beach/pool score favors clear, rainless days with daytime highs between 24°C and 34°C. Based on this score, the best time of year to visit San Marcos for hot-weather activities is from mid January to late March, with a peak score in the last week of February.
The beach/pool score (filled area), and its constituents: the temperature score (red line), the cloud cover score (blue line), and the precipitation score (green line).
What to pack for San Marcos, by month
Month by month, what's worth putting in the bag — from the temperature range, rain chance, sun and wind. Tap a month for a quick packing note.
San Marcos packs about the same all year — highs hold near 21°C. Across the year the things worth having are rain gear and sun protection.
In April, San Marcos sees daytime highs around 21°C and nights near 12°C. Pack rain gear and sun protection. About 24 days see rain.
UV index (midday) in San Marcos by month
Clear-sky midday UV index through the year, shaded by the WHO exposure levels — how much sun protection each month calls for.
Under clear skies, the midday UV index in San Marcos peaks around April 12 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 16 at about 9 (very high).
The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 9 | 13 | 14 | 14 | 12 | 13 | 13 | 13 | 12 | 11 | 9 | 9 |
| Level | Very high | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Extreme | Very high | Very high |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 9 | Very high |
| Feb | 13 | Extreme |
| Mar | 14 | Extreme |
| Apr | 14 | Extreme |
| May | 12 | Extreme |
| Jun | 13 | Extreme |
| Jul | 13 | Extreme |
| Aug | 13 | Extreme |
| Sep | 12 | Extreme |
| Oct | 11 | Extreme |
| Nov | 9 | Very high |
| Dec | 9 | Very high |
Average hourly UV index in San Marcos
Modeled clear-sky UV for every hour of every day — when in the day sun protection actually matters.
The whole year hour by hour: each column is a day, each row an hour, and the color is the modeled clear-sky UV index — the midday peak scaled down as the sun sits lower in the sky. Darker overlays mark night, lighter ones the civil-twilight hours around sunrise and sunset.
UV falls off far faster than brightness as the sun drops, so even in April the burn window is concentrated in the middle of the day: about 8 hours a day reach index 3 (protection recommended), and 6.5 hours reach 6 or more. Mornings and late afternoons stay comparatively gentle year round.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV ≥ 3 (h/day) | 7 | 7.5 | 8 | 8 | 8.5 | 8.5 | 8.5 | 8 | 8 | 7.5 | 7 | 6.5 |
| UV ≥ 6 (h/day) | 5 | 6 | 6.5 | 6.5 | 6 | 6.5 | 6.5 | 6.5 | 6 | 5.5 | 4.5 | 4.5 |
| UV ≥ 3 (h/day) | UV ≥ 6 (h/day) | |
|---|---|---|
| Jan | 7 | 5 |
| Feb | 7.5 | 6 |
| Mar | 8 | 6.5 |
| Apr | 8 | 6.5 |
| May | 8.5 | 6 |
| Jun | 8.5 | 6.5 |
| Jul | 8.5 | 6.5 |
| Aug | 8 | 6.5 |
| Sep | 8 | 6 |
| Oct | 7.5 | 5.5 |
| Nov | 7 | 4.5 |
| Dec | 6.5 | 4.5 |
Air quality in San Marcos by month
Average fine-particle pollution (PM2.5) through the year — so you can see which months the air is worst, not just the yearly average.
Air quality in San Marcos is worst in May — around 34 µg/m³ PM2.5 (moderate), and holds fairly steady the rest of the year.
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 23 | 22 | 25 | 34 | 34 | 23 | 23 | 22 | 23 | 23 | 23 | 25 |
| Level | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate | Moderate |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 23 | Moderate |
| Feb | 22 | Moderate |
| Mar | 25 | Moderate |
| Apr | 34 | Moderate |
| May | 34 | Moderate |
| Jun | 23 | Moderate |
| Jul | 23 | Moderate |
| Aug | 22 | Moderate |
| Sep | 23 | Moderate |
| Oct | 23 | Moderate |
| Nov | 23 | Moderate |
| Dec | 25 | Moderate |
Growing season
San Marcos is frost-free year round — even the coldest nights rarely reach freezing, so there is no start or end to the growing season.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Frost-free chance (%) | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 | 100 |
| Frost nights | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 |
| Frost-free chance (%) | Frost nights | |
|---|---|---|
| Jan | 100 | 0 |
| Feb | 100 | 0 |
| Mar | 100 | 0 |
| Apr | 100 | 0 |
| May | 100 | 0 |
| Jun | 100 | 0 |
| Jul | 100 | 0 |
| Aug | 100 | 0 |
| Sep | 100 | 0 |
| Oct | 100 | 0 |
| Nov | 100 | 0 |
| Dec | 100 | 0 |
Growing degree days
Growing degree days tally heat above 10°C: each day adds however many degrees its average temperature runs over that threshold, and cold days add nothing. San Marcos banks about 2,155 degree days a year, and the running total — which growers use to time plantings and predict maturity — climbs fastest around May.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Growing degree days (°C·days) | 142 | 146 | 181 | 194 | 211 | 198 | 193 | 196 | 193 | 191 | 162 | 146 |
| Growing degree days (°C·days) | |
|---|---|
| Jan | 142 |
| Feb | 146 |
| Mar | 181 |
| Apr | 194 |
| May | 211 |
| Jun | 198 |
| Jul | 193 |
| Aug | 196 |
| Sep | 193 |
| Oct | 191 |
| Nov | 162 |
| Dec | 146 |
Solar energy
Average daily shortwave solar energy reaching the ground, banded into brightness zones so the number means something at a glance.
Solar energy is how much sunlight actually reaches the ground each day, measured in kilowatt-hours per square metre (kWh/m²) — the combined effect of how long the sun is up, how high it climbs, and how much cloud gets in the way. It's the raw fuel a solar panel has to work with: for scale, 1 kWh/m² a day is dim and wintry, while 7+ is desert-bright.
San Marcos receives about 5.3 kWh/m² a day of solar energy on average — bright — with a clear seasonal swing between 4.4 and 6.3 kWh/m².
The brighter stretch of the year lasts 3.9 months, from around Jan 21 to May 20. The brightest month is April, averaging about 6.2 kWh/m² (intense).
The dimmest month is October, down near 4.5 kWh/m² — roughly 28% less than the April peak.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Solar energy (kWh/m²) | 5.2 | 5.8 | 6.2 | 6.2 | 5.5 | 4.9 | 5.5 | 5.3 | 4.7 | 4.5 | 4.8 | 4.9 |
| Level | Bright | Bright | Intense | Intense | Bright | Bright | Bright | Bright | Bright | Bright | Bright | Bright |
| Solar energy (kWh/m²) | Level | |
|---|---|---|
| Jan | 5.2 | Bright |
| Feb | 5.8 | Bright |
| Mar | 6.2 | Intense |
| Apr | 6.2 | Intense |
| May | 5.5 | Bright |
| Jun | 4.9 | Bright |
| Jul | 5.5 | Bright |
| Aug | 5.3 | Bright |
| Sep | 4.7 | Bright |
| Oct | 4.5 | Bright |
| Nov | 4.8 | Bright |
| Dec | 4.9 | Bright |
Where is San Marcos?
San Marcos sits at 15.0°N, 91.8°W, 2,380 m above sea level, in Guatemala. The nearest listed city is San Pedro Sacatepéquez, 4.0 km away.
Topography around San Marcos
How much the land rises and falls, and what covers it, within 3, 16 and 80 km of San Marcos.
Within 3 km, the terrain around San Marcos has large variations in elevation — a maximum elevation change of 814 m around an average of 2,422 m above sea level; within 16 km, extreme variations in elevation — a maximum elevation change of 3,414 m; within 80 km, extreme variations in elevation — a maximum elevation change of 4,178 m.
The land around San Marcos is covered by trees (47%), artificial surfaces (30%) and cropland (22%) within 3 km, trees (80%) within 16 km, and trees (69%) within 80 km.
Guatemala travel facts
- Travel advisory
- Level 3
- Reconsider Travel
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 43% of US
- price level, 2025
- GDP per capita
- $6,598
- 2025
- Happiness
- 6.5 / 10
- World Happiness, 2025
- Safe drinking water
- 49%
- of population, 2024
- Homicide rate
- 23.4
- per 100k, 2023
- Road deaths
- 22.9
- per 100k/yr, 2019
- Income group
- Upper middle
- World Bank
- English
- Moderate
- EF EPI 510
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for San Marcos (14.9644°, -91.7949°, elevation 2,380 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).