San Martín weather in September

In September, San Martín sees average daytime highs of 28°C and overnight lows near 21°C, with 506 mm of rain across 29.8 wet days and about 12 hours of daylight. It is the 9th-warmest and 5th-wettest month of the year here.

Day-to-day highs hold fairly steady near 28°C through the month. The sky is clear or mostly clear about 0% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 12 h 12 min at the start of September to 11 h 54 min by month's end. Set against the rest of the year, September is San Martín's 10th-clearest and 3rd-windiest month. For the whole year in context, see San Martín's year-round climate.

Daytime high: 28°; 9th warmest
Overnight low: 21°; 5th coldest
Rainfall: 506 mm; 29.8 wet days
Daylight: 12 hours; 5:47 AM – 5:50 PM
Cloud cover: 93%; 10th clearest
Wind: 4 km/h; 3rd windiest
Solar energy: 5.08 kWh/m²
Travel score: 3.2; out of 10

San Martín is municipality in Cesar, Colombia.

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

← August San Martín year-round climate October →Best places to visit in September

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 28°C through the month.

A typical September day in San Martín reaches about 28°C in the afternoon and slips back to 21°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 26°C and 29°C. Set against its neighbours, September runs on par with August and on par with October.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Avg high (°C)	28	28	28	28	28	28	28	28	28	28	28	28	28	28	28	28	28	28	28	28	28	28	28	28	28	28	28	28	28	28
Avg low (°C)	21	21	21	21	21	21	21	21	21	21	21	21	21	21	21	21	21	21	21	21	21	21	21	21	21	21	21	21	21	21

	Avg high (°C)	Avg low (°C)
1	28	21
2	28	21
3	28	21
4	28	21
5	28	21
6	28	21
7	28	21
8	28	21
9	28	21
10	28	21
11	28	21
12	28	21
13	28	21
14	28	21
15	28	21
16	28	21
17	28	21
18	28	21
19	28	21
20	28	21
21	28	21
22	28	21
23	28	21
24	28	21
25	28	21
26	28	21
27	28	21
28	28	21
29	28	21
30	28	21

San Martín weather by month

How September compares with the rest of the year at a glance. September is the 9th-warmest and 5th-wettest month here — the current month is highlighted below.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Daylight (hours)	Travel score
Jan	29° / 21°	111	20.2	11.6	4.5
Feb	29° / 21°	143	18.7	11.7	4.1
Mar	29° / 22°	275	26.6	11.9	3.4
Apr	28° / 22°	478	29.6	12.2	2.9
May	28° / 22°	644	30.7	12.4	3.0
Jun	28° / 21°	617	29.8	12.5	3.1
Jul	28° / 21°	591	30.8	12.4	3.2
Aug	28° / 21°	588	31	12.3	3.1
Sep	28° / 21°	506	29.8	12	3.2
Oct	28° / 21°	452	30.1	11.8	3.3
Nov	28° / 21°	378	29	11.6	3.3
Dec	28° / 21°	206	26.2	11.5	3.8

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 0% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 2% of September, with mostly cloudy or overcast conditions the remaining 98%.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Clearer (%)	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	2	1	1	1	1	1	1	1
Cloudier (%)	98	98	98	98	98	98	98	98	98	98	98	98	98	98	98	98	98	98	98	98	98	98	98	99	99	99	99	99	99	99

	Clearer (%)	Cloudier (%)
1	2	98
2	2	98
3	2	98
4	2	98
5	2	98
6	2	98
7	2	98
8	2	98
9	2	98
10	2	98
11	2	98
12	2	98
13	2	98
14	2	98
15	2	98
16	2	98
17	2	98
18	2	98
19	2	98
20	2	98
21	2	98
22	2	98
23	2	98
24	1	99
25	1	99
26	1	99
27	1	99
28	1	99
29	1	99
30	1	99

Chance of precipitation in September

Any precipitation

San Martín gets around 506 mm of rain over 29.8 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 99% and peaks near 100% on the wettest days.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Rain chance (%)	99	99	99	99	99	99	99	99	99	99	99	99	99	99	99	99	99	99	99	100	100	100	100	100	100	99	99	99	99	99

	Rain chance (%)
1	99
2	99
3	99
4	99
5	99
6	99
7	99
8	99
9	99
10	99
11	99
12	99
13	99
14	99
15	99
16	99
17	99
18	99
19	99
20	100
21	100
22	100
23	100
24	100
25	100
26	99
27	99
28	99
29	99
30	99

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

Most of September feels oppressive — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, September lands in the oppressive band about 83% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Muggy (%)	16	16	16	16	17	17	16	16	16	16	16	16	16	15	15	15	15	15	16	16	16	17	17	18	18	19	19	19	19	20
Oppressive (%)	84	84	84	84	83	83	84	84	84	84	84	84	84	85	85	85	85	85	84	84	84	83	83	82	82	81	81	81	81	80

	Muggy (%)	Oppressive (%)
1	16	84
2	16	84
3	16	84
4	16	84
5	17	83
6	17	83
7	16	84
8	16	84
9	16	84
10	16	84
11	16	84
12	16	84
13	16	84
14	15	85
15	15	85
16	15	85
17	15	85
18	15	85
19	16	84
20	16	84
21	16	84
22	17	83
23	17	83
24	18	82
25	18	82
26	19	81
27	19	81
28	19	81
29	19	81
30	20	80

Wind in September

Winds average 4 km/h in September.

Across September, daily wind ranges from about 4 km/h on the calmest days to 4 km/h at its breeziest. It stays fairly steady from day to day.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Wind speed (km/h)	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4
Feels	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm

	Wind speed (km/h)	Feels
1	4	calm
2	4	calm
3	4	calm
4	4	calm
5	4	calm
6	4	calm
7	4	calm
8	4	calm
9	4	calm
10	4	calm
11	4	calm
12	4	calm
13	4	calm
14	4	calm
15	4	calm
16	4	calm
17	4	calm
18	4	calm
19	4	calm
20	4	calm
21	4	calm
22	4	calm
23	4	calm
24	4	calm
25	4	calm
26	4	calm
27	4	calm
28	4	calm
29	4	calm
30	4	calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 12 min at the start of September to 11 h 54 min by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 18 minutes over September. Sunrise moves from 5:49 AM to 5:45 AM, and sunset from 5:58 PM to 5:41 PM.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Daylight (h)	12.2	12.1	12.1	12.1	12.1	12.1	12.1	12.1	12.1	12.1	12.1	12.1	12.1	12.1	12.1	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	11.9	11.9
Sunrise (AM)	5:49	5:49	5:49	5:49	5:49	5:48	5:48	5:48	5:48	5:48	5:48	5:48	5:48	5:47	5:47	5:47	5:47	5:47	5:47	5:46	5:46	5:46	5:46	5:46	5:46	5:46	5:46	5:45	5:45	5:45
Sunset (PM)	5:58	5:58	5:57	5:57	5:56	5:56	5:55	5:54	5:54	5:53	5:53	5:52	5:51	5:51	5:50	5:50	5:49	5:48	5:48	5:47	5:47	5:46	5:46	5:45	5:44	5:44	5:43	5:43	5:42	5:41

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	12.2	5:49	5:58
2	12.1	5:49	5:58
3	12.1	5:49	5:57
4	12.1	5:49	5:57
5	12.1	5:49	5:56
6	12.1	5:48	5:56
7	12.1	5:48	5:55
8	12.1	5:48	5:54
9	12.1	5:48	5:54
10	12.1	5:48	5:53
11	12.1	5:48	5:53
12	12.1	5:48	5:52
13	12.1	5:48	5:51
14	12.1	5:47	5:51
15	12.1	5:47	5:50
16	12.0	5:47	5:50
17	12.0	5:47	5:49
18	12.0	5:47	5:48
19	12.0	5:47	5:48
20	12.0	5:46	5:47
21	12.0	5:46	5:47
22	12.0	5:46	5:46
23	12.0	5:46	5:46
24	12.0	5:46	5:45
25	12.0	5:46	5:44
26	12.0	5:46	5:44
27	12.0	5:46	5:43
28	12.0	5:45	5:43
29	11.9	5:45	5:42
30	11.9	5:45	5:41

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.08 kWh/m².

For context, solar energy here swings from a low near 4.3 kWh/m² to a high of 5.68 kWh/m² in February across the year — September's 5.08 kWh/m² falls in the middle.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Solar energy (kWh/m²)	5.3	5.3	5.3	5.3	5.3	5.3	5.3	5.2	5.2	5.2	5.2	5.2	5.1	5.1	5.1	5.1	5.0	5.0	5.0	5.0	5.0	4.9	4.9	4.9	4.9	4.9	4.9	4.8	4.8	4.8
Level	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright

	Solar energy (kWh/m²)	Level
1	5.3	Bright
2	5.3	Bright
3	5.3	Bright
4	5.3	Bright
5	5.3	Bright
6	5.3	Bright
7	5.3	Bright
8	5.2	Bright
9	5.2	Bright
10	5.2	Bright
11	5.2	Bright
12	5.2	Bright
13	5.1	Bright
14	5.1	Bright
15	5.1	Bright
16	5.1	Bright
17	5.0	Bright
18	5.0	Bright
19	5.0	Bright
20	5.0	Bright
21	5.0	Bright
22	4.9	Bright
23	4.9	Bright
24	4.9	Bright
25	4.9	Bright
26	4.9	Bright
27	4.9	Bright
28	4.8	Bright
29	4.8	Bright
30	4.8	Bright

Planning a trip in September

Is September a good time to visit San Martín?

Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

3.2

Sightseeing

7th-best month of the year

3.4

Beach & pool

11th-best month of the year

September is a weaker month for outdoor sightseeing in San Martín.

What to pack for San Martín in September

From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In September, San Martín sees daytime highs around 28°C and nights near 21°C. Pack light clothes and rain gear. Worth having: sun protection. About 30 days see rain.

light clothesrain gearsun protection

UV index in San Martín in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 13 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in San Martín peaks around February 16 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 13 at about 10 (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)	11	13	12	11	12	13	12	12	13	12	10	10
Level	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Very high

	UV index (midday)	Level
Jan	11	Extreme
Feb	13	Extreme
Mar	12	Extreme
Apr	11	Extreme
May	12	Extreme
Jun	13	Extreme
Jul	12	Extreme
Aug	12	Extreme
Sep	13	Extreme
Oct	12	Extreme
Nov	10	Extreme
Dec	10	Very high

Air quality in San Martín in September

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.

Air quality in San Martín is worst in March — around 46 µg/m³ PM2.5 (poor), about 3.7× the cleanest month (December, 13 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
PM2.5 (µg/m³)	16	26	46	32	23	21	21	19	16	14	13	13
Level	Moderate	Moderate	Poor	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate

	PM2.5 (µg/m³)	Level
Jan	16	Moderate
Feb	26	Moderate
Mar	46	Poor
Apr	32	Moderate
May	23	Moderate
Jun	21	Moderate
Jul	21	Moderate
Aug	19	Moderate
Sep	16	Moderate
Oct	14	Moderate
Nov	13	Moderate
Dec	13	Moderate

Location & terrain

Where is San Martín?

San Martín sits at 8.0°N, 73.5°W, 112 m above sea level, in Colombia. The nearest listed city is Ocaña, 31 km away.

Topography around San Martín

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of San Martín.

Within 3 km, the terrain around San Martín has only modest variations in elevation — a maximum elevation change of 53 m around an average of 105 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,315 m; within 80 km, extreme variations in elevation — a maximum elevation change of 3,956 m.

The land around San Martín is covered by grassland (63%) and trees (32%) within 3 km, grassland (58%) and trees (41%) within 16 km, and trees (58%) and grassland (40%) within 80 km.

3 km

53 m

grassland 63%

16 km

1,315 m

grassland 58%

80 km

3,956 m

trees 58%

treesgrasslandcroplandartificial surfacesbare terrainwater

← August San Martín year-round climate October →Best places to visit in September

September weather nearby: Ocaña 31 km · Aguachica 36 km · Simití 48 km · Morales 50 km · Sabana de Torres 68 km · Puerto Wilches 84 km · El Zulia 101 km · Tiquisio 103 km

Colombia travel facts

Travel advisory: Level 3; Reconsider Travel
Power plugs: Type A / B; 120 / 240 V · 60 Hz
Prices: ≈ 38% of US; price level, 2025
GDP per capita: $8,562; 2025
Happiness: 6.0 / 10; World Happiness, 2025
Safe drinking water: 74%; of population, 2024
Homicide rate: 24.9; per 100k, 2023
Road deaths: 15.4; per 100k/yr, 2019
Income group: Upper middle; World Bank
English: Low; EF EPI 480
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 Martín (8.0018°, -73.5114°, elevation 112 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).

	Avg high (°C)	Avg low (°C)
1	28	21
2	28	21
3	28	21
4	28	21
5	28	21
6	28	21
7	28	21
8	28	21
9	28	21
10	28	21
11	28	21
12	28	21
13	28	21
14	28	21
15	28	21
16	28	21
17	28	21
18	28	21
19	28	21
20	28	21
21	28	21
22	28	21
23	28	21
24	28	21
25	28	21
26	28	21
27	28	21
28	28	21
29	28	21
30	28	21

	Clearer (%)	Cloudier (%)
1	2	98
2	2	98
3	2	98
4	2	98
5	2	98
6	2	98
7	2	98
8	2	98
9	2	98
10	2	98
11	2	98
12	2	98
13	2	98
14	2	98
15	2	98
16	2	98
17	2	98
18	2	98
19	2	98
20	2	98
21	2	98
22	2	98
23	2	98
24	1	99
25	1	99
26	1	99
27	1	99
28	1	99
29	1	99
30	1	99

	Rain chance (%)
1	99
2	99
3	99
4	99
5	99
6	99
7	99
8	99
9	99
10	99
11	99
12	99
13	99
14	99
15	99
16	99
17	99
18	99
19	99
20	100
21	100
22	100
23	100
24	100
25	100
26	99
27	99
28	99
29	99
30	99

	Muggy (%)	Oppressive (%)
1	16	84
2	16	84
3	16	84
4	16	84
5	17	83
6	17	83
7	16	84
8	16	84
9	16	84
10	16	84
11	16	84
12	16	84
13	16	84
14	15	85
15	15	85
16	15	85
17	15	85
18	15	85
19	16	84
20	16	84
21	16	84
22	17	83
23	17	83
24	18	82
25	18	82
26	19	81
27	19	81
28	19	81
29	19	81
30	20	80

	Avg high (°C)	Avg low (°C)
1	28	21
2	28	21
3	28	21
4	28	21
5	28	21
6	28	21
7	28	21
8	28	21
9	28	21
10	28	21
11	28	21
12	28	21
13	28	21
14	28	21
15	28	21
16	28	21
17	28	21
18	28	21
19	28	21
20	28	21
21	28	21
22	28	21
23	28	21
24	28	21
25	28	21
26	28	21
27	28	21
28	28	21
29	28	21
30	28	21

	Clearer (%)	Cloudier (%)
1	2	98
2	2	98
3	2	98
4	2	98
5	2	98
6	2	98
7	2	98
8	2	98
9	2	98
10	2	98
11	2	98
12	2	98
13	2	98
14	2	98
15	2	98
16	2	98
17	2	98
18	2	98
19	2	98
20	2	98
21	2	98
22	2	98
23	2	98
24	1	99
25	1	99
26	1	99
27	1	99
28	1	99
29	1	99
30	1	99

	Rain chance (%)
1	99
2	99
3	99
4	99
5	99
6	99
7	99
8	99
9	99
10	99
11	99
12	99
13	99
14	99
15	99
16	99
17	99
18	99
19	99
20	100
21	100
22	100
23	100
24	100
25	100
26	99
27	99
28	99
29	99
30	99

	Muggy (%)	Oppressive (%)
1	16	84
2	16	84
3	16	84
4	16	84
5	17	83
6	17	83
7	16	84
8	16	84
9	16	84
10	16	84
11	16	84
12	16	84
13	16	84
14	15	85
15	15	85
16	15	85
17	15	85
18	15	85
19	16	84
20	16	84
21	16	84
22	17	83
23	17	83
24	18	82
25	18	82
26	19	81
27	19	81
28	19	81
29	19	81
30	20	80

	Avg high (°C)	Avg low (°C)
1	28	21
2	28	21
3	28	21
4	28	21
5	28	21
6	28	21
7	28	21
8	28	21
9	28	21
10	28	21
11	28	21
12	28	21
13	28	21
14	28	21
15	28	21
16	28	21
17	28	21
18	28	21
19	28	21
20	28	21
21	28	21
22	28	21
23	28	21
24	28	21
25	28	21
26	28	21
27	28	21
28	28	21
29	28	21
30	28	21

	Clearer (%)	Cloudier (%)
1	2	98
2	2	98
3	2	98
4	2	98
5	2	98
6	2	98
7	2	98
8	2	98
9	2	98
10	2	98
11	2	98
12	2	98
13	2	98
14	2	98
15	2	98
16	2	98
17	2	98
18	2	98
19	2	98
20	2	98
21	2	98
22	2	98
23	2	98
24	1	99
25	1	99
26	1	99
27	1	99
28	1	99
29	1	99
30	1	99

	Rain chance (%)
1	99
2	99
3	99
4	99
5	99
6	99
7	99
8	99
9	99
10	99
11	99
12	99
13	99
14	99
15	99
16	99
17	99
18	99
19	99
20	100
21	100
22	100
23	100
24	100
25	100
26	99
27	99
28	99
29	99
30	99

	Muggy (%)	Oppressive (%)
1	16	84
2	16	84
3	16	84
4	16	84
5	17	83
6	17	83
7	16	84
8	16	84
9	16	84
10	16	84
11	16	84
12	16	84
13	16	84
14	15	85
15	15	85
16	15	85
17	15	85
18	15	85
19	16	84
20	16	84
21	16	84
22	17	83
23	17	83
24	18	82
25	18	82
26	19	81
27	19	81
28	19	81
29	19	81
30	20	80