San Onofre weather in September

In September, San Onofre sees average daytime highs of 29°C and overnight lows near 25°C, with 220 mm of rain across 28.2 wet days and about 12.1 hours of daylight. It is the 10th-warmest and 3rd-wettest month of the year here.

Day-to-day highs hold fairly steady near 29°C through the month. The sky is clear or mostly clear about 1% of the time in September, and the air most often feels miserable.

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 Onofre's 11th-clearest and 9th-windiest month. For the whole year in context, see San Onofre's year-round climate.

Daytime high: 29°; 10th warmest
Overnight low: 25°; 6th coldest
Rainfall: 220 mm; 28.2 wet days
Daylight: 12 h 06 min; 5:55 AM – 5:58 PM
Cloud cover: 90%; 11th clearest
Wind: 8 km/h; 9th windiest
Solar energy: 4.92 kWh/m²
Travel score: 2.9; out of 10

← August San Onofre 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 29°C through the month.

A typical September day in San Onofre reaches about 29°C in the afternoon and slips back to 25°C overnight — a 4°C spread between the day's warmth and the night's chill. On most days the high lands between 28°C and 30°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)	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29	29
Avg low (°C)	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25

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

How September really feels in San Onofre

Once humidity and wind are folded in, September averages 30 days that feel above 32°C and 0 that feel at or below 0°C — the comfort signal a plain temperature reading hides.

Days feeling ≥ 32°C

heat index over the day's high

Days feeling ≤ 0°C

wind chill below the day's low

The story in September is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

San Onofre weather by month

How September compares with the rest of the year at a glance. September is the 10th-warmest and 3rd-wettest month here — the current month is highlighted below.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Daylight (hours)	Travel score
Jan	30° / 24°	19	5.1	11.5	5.6
Feb	31° / 25°	20	5.6	11.7	5.1
Mar	31° / 25°	43	12	11.9	4.5
Apr	30° / 25°	119	22.3	12.2	3.4
May	30° / 25°	220	28.2	12.4	2.9
Jun	30° / 25°	210	26.1	12.6	2.9
Jul	30° / 25°	189	25.7	12.5	3.0
Aug	30° / 25°	207	27.3	12.3	2.9
Sep	29° / 25°	220	28.2	12.1	2.9
Oct	29° / 25°	251	29	11.8	3.0
Nov	29° / 25°	190	25.1	11.6	3.4
Dec	30° / 25°	80	14.3	11.4	4.7

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 1% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 5% of September, with mostly cloudy or overcast conditions the remaining 94%.

	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 (%)	6	6	6	6	6	6	6	5	5	5	5	5	5	5	5	5	6	6	6	6	6	6	6	6	6	6	6	6	6	6
Cloudier (%)	94	94	94	94	94	94	94	95	95	95	95	95	95	95	95	95	94	94	94	94	94	94	94	94	94	94	94	94	94	94

	Clearer (%)	Cloudier (%)
1	6	94
2	6	94
3	6	94
4	6	94
5	6	94
6	6	94
7	6	94
8	5	95
9	5	95
10	5	95
11	5	95
12	5	95
13	5	95
14	5	95
15	5	95
16	5	95
17	6	94
18	6	94
19	6	94
20	6	94
21	6	94
22	6	94
23	6	94
24	6	94
25	6	94
26	6	94
27	6	94
28	6	94
29	6	94
30	6	94

Chance of precipitation in September

Any precipitation

San Onofre gets around 220 mm of rain over 28.2 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 94% and peaks near 95% 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 (%)	92	92	92	92	92	92	93	93	93	93	93	94	94	94	94	94	94	95	95	95	95	95	95	95	95	94	94	94	94	94

	Rain chance (%)
1	92
2	92
3	92
4	92
5	92
6	92
7	93
8	93
9	93
10	93
11	93
12	94
13	94
14	94
15	94
16	94
17	94
18	95
19	95
20	95
21	95
22	95
23	95
24	95
25	95
26	94
27	94
28	94
29	94
30	94

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the miserable band about 59% 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
Oppressive (%)	36	36	36	36	36	36	36	37	37	37	37	38	38	38	39	39	40	41	42	43	43	44	45	46	46	47	47	47	48	48
Miserable (%)	64	64	64	64	64	64	64	63	63	63	63	62	62	62	61	61	60	59	58	57	57	56	55	54	54	53	53	53	52	52

	Oppressive (%)	Miserable (%)
1	36	64
2	36	64
3	36	64
4	36	64
5	36	64
6	36	64
7	36	64
8	37	63
9	37	63
10	37	63
11	37	63
12	38	62
13	38	62
14	38	62
15	39	61
16	39	61
17	40	60
18	41	59
19	42	58
20	43	57
21	43	57
22	44	56
23	45	55
24	46	54
25	46	54
26	47	53
27	47	53
28	47	53
29	48	52
30	48	52

Wind in September

Winds average 8 km/h in September.

Across September, daily wind ranges from about 8 km/h on the calmest days to 8 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)	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8	8
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	8	calm
2	8	calm
3	8	calm
4	8	calm
5	8	calm
6	8	calm
7	8	calm
8	8	calm
9	8	calm
10	8	calm
11	8	calm
12	8	calm
13	8	calm
14	8	calm
15	8	calm
16	8	calm
17	8	calm
18	8	calm
19	8	calm
20	8	calm
21	8	calm
22	8	calm
23	8	calm
24	8	calm
25	8	calm
26	8	calm
27	8	calm
28	8	calm
29	8	calm
30	8	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 5:56 AM to 5:54 AM, and sunset from 6:07 PM to 5:49 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	12.2	12.2	12.2	12.2	12.1	12.1	12.1	12.1	12.1	12.1	12.1	12.1	12.1	12.1	12.1	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	11.9	11.9	11.9
Sunrise (AM)	5:56	5:56	5:56	5:56	5:56	5:56	5:56	5:56	5:56	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:54	5:54	5:54	5:54	5:54	5:54	5:54	5:54	5:54	5:54	5:54
Sunset (PM)	6:07	6:07	6:06	6:06	6:05	6:04	6:04	6:03	6:03	6:02	6:01	6:01	6:00	5:59	5:59	5:58	5:57	5:57	5:56	5:55	5:55	5:54	5:54	5:53	5:52	5:52	5:51	5:50	5:50	5:49

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	12.2	5:56	6:07
2	12.2	5:56	6:07
3	12.2	5:56	6:06
4	12.2	5:56	6:06
5	12.2	5:56	6:05
6	12.1	5:56	6:04
7	12.1	5:56	6:04
8	12.1	5:56	6:03
9	12.1	5:56	6:03
10	12.1	5:55	6:02
11	12.1	5:55	6:01
12	12.1	5:55	6:01
13	12.1	5:55	6:00
14	12.1	5:55	5:59
15	12.1	5:55	5:59
16	12.1	5:55	5:58
17	12.0	5:55	5:57
18	12.0	5:55	5:57
19	12.0	5:55	5:56
20	12.0	5:54	5:55
21	12.0	5:54	5:55
22	12.0	5:54	5:54
23	12.0	5:54	5:54
24	12.0	5:54	5:53
25	12.0	5:54	5:52
26	12.0	5:54	5:52
27	12.0	5:54	5:51
28	11.9	5:54	5:50
29	11.9	5:54	5:50
30	11.9	5:54	5:49

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.92 kWh/m².

For context, solar energy here swings from a low near 4.48 kWh/m² to a high of 5.97 kWh/m² in March across the year — September's 4.92 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)	5.0	5.0	5.0	5.0	5.0	5.0	5.0	5.0	5.0	5.0	5.0	5.0	5.0	4.9	4.9	4.9	4.9	4.9	4.9	4.9	4.9	4.8	4.8	4.8	4.8	4.8	4.8	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	5.0	Bright
2	5.0	Bright
3	5.0	Bright
4	5.0	Bright
5	5.0	Bright
6	5.0	Bright
7	5.0	Bright
8	5.0	Bright
9	5.0	Bright
10	5.0	Bright
11	5.0	Bright
12	5.0	Bright
13	5.0	Bright
14	4.9	Bright
15	4.9	Bright
16	4.9	Bright
17	4.9	Bright
18	4.9	Bright
19	4.9	Bright
20	4.9	Bright
21	4.9	Bright
22	4.8	Bright
23	4.8	Bright
24	4.8	Bright
25	4.8	Bright
26	4.8	Bright
27	4.8	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 Onofre?

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

2.9

Sightseeing

9th-best month of the year

3.8

Beach & pool

12th-best month of the year

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

What to pack for San Onofre in September

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

In September, San Onofre sees daytime highs around 29°C and nights near 25°C. Pack light clothes and rain gear. Worth having: sun protection. About 28 days see rain.

light clothesrain gearsun protection

Sea temperature near San Onofre in September

The nearest coast averages about 30°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 16 km away) is warmest in July at about 30°C and coldest in March near 28°C.

The water stays above 20°C all year — warm enough for a swim any month.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Sea temperature (°C)	29	28	28	29	29	30	30	30	30	29	29	29
Comfort	Tropical	Tropical	Tropical	Tropical	Tropical	Tropical	Tropical	Tropical	Tropical	Tropical	Tropical	Tropical

	Sea temperature (°C)	Comfort
Jan	29	Tropical
Feb	28	Tropical
Mar	28	Tropical
Apr	29	Tropical
May	29	Tropical
Jun	30	Tropical
Jul	30	Tropical
Aug	30	Tropical
Sep	30	Tropical
Oct	29	Tropical
Nov	29	Tropical
Dec	29	Tropical

UV index in San Onofre in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 12 (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 Onofre peaks around June 10 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	12	12	12	13	13	11	12	12	12	10	10
Level	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Very high	Very high

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

Air quality in San Onofre 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 Onofre is worst in July — around 26 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (November, 11 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)	14	18	26	25	25	23	26	20	14	12	11	14
Level	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Moderate	Good	Good	Moderate

	PM2.5 (µg/m³)	Level
Jan	14	Moderate
Feb	18	Moderate
Mar	26	Moderate
Apr	25	Moderate
May	25	Moderate
Jun	23	Moderate
Jul	26	Moderate
Aug	20	Moderate
Sep	14	Moderate
Oct	12	Good
Nov	11	Good
Dec	14	Moderate

Location & terrain

Where is San Onofre?

San Onofre sits at 9.7°N, 75.5°W, 37 m above sea level, in Colombia. The nearest listed city is Santiago de Tolú, 24 km away.

Topography around San Onofre

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

Within 3 km, the terrain around San Onofre has only modest variations in elevation — a maximum elevation change of 53 m around an average of 27 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 232 m; within 80 km, large variations in elevation — a maximum elevation change of 810 m.

The land around San Onofre is covered by grassland (79%) within 3 km, grassland (52%) and trees (33%) within 16 km, and grassland (39%), water (32%) and trees (23%) within 80 km.

3 km

53 m

grassland 79%

16 km

232 m

grassland 52%

80 km

810 m

grassland 39%

treesshrubsgrasslandartificial surfaceswaterwetlandmangroves

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

September weather nearby: Santiago de Tolú 24 km · Tolú Viejo 33 km · María la Baja 37 km · El Carmen de Bolívar 45 km · San Pablo 45 km · San Jacinto 45 km · San Antero 48 km · Sincelejo 50 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 Onofre (9.7359°, -75.5263°, elevation 37 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. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. 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	29	25
2	29	25
3	29	25
4	29	25
5	29	25
6	29	25
7	29	25
8	29	25
9	29	25
10	29	25
11	29	25
12	29	25
13	29	25
14	29	25
15	29	25
16	29	25
17	29	25
18	29	25
19	29	25
20	29	25
21	29	25
22	29	25
23	29	25
24	29	25
25	29	25
26	29	25
27	29	25
28	29	25
29	29	25
30	29	25

	Clearer (%)	Cloudier (%)
1	6	94
2	6	94
3	6	94
4	6	94
5	6	94
6	6	94
7	6	94
8	5	95
9	5	95
10	5	95
11	5	95
12	5	95
13	5	95
14	5	95
15	5	95
16	5	95
17	6	94
18	6	94
19	6	94
20	6	94
21	6	94
22	6	94
23	6	94
24	6	94
25	6	94
26	6	94
27	6	94
28	6	94
29	6	94
30	6	94

	Rain chance (%)
1	92
2	92
3	92
4	92
5	92
6	92
7	93
8	93
9	93
10	93
11	93
12	94
13	94
14	94
15	94
16	94
17	94
18	95
19	95
20	95
21	95
22	95
23	95
24	95
25	95
26	94
27	94
28	94
29	94
30	94

	Oppressive (%)	Miserable (%)
1	36	64
2	36	64
3	36	64
4	36	64
5	36	64
6	36	64
7	36	64
8	37	63
9	37	63
10	37	63
11	37	63
12	38	62
13	38	62
14	38	62
15	39	61
16	39	61
17	40	60
18	41	59
19	42	58
20	43	57
21	43	57
22	44	56
23	45	55
24	46	54
25	46	54
26	47	53
27	47	53
28	47	53
29	48	52
30	48	52

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

	Clearer (%)	Cloudier (%)
1	6	94
2	6	94
3	6	94
4	6	94
5	6	94
6	6	94
7	6	94
8	5	95
9	5	95
10	5	95
11	5	95
12	5	95
13	5	95
14	5	95
15	5	95
16	5	95
17	6	94
18	6	94
19	6	94
20	6	94
21	6	94
22	6	94
23	6	94
24	6	94
25	6	94
26	6	94
27	6	94
28	6	94
29	6	94
30	6	94

	Rain chance (%)
1	92
2	92
3	92
4	92
5	92
6	92
7	93
8	93
9	93
10	93
11	93
12	94
13	94
14	94
15	94
16	94
17	94
18	95
19	95
20	95
21	95
22	95
23	95
24	95
25	95
26	94
27	94
28	94
29	94
30	94

	Oppressive (%)	Miserable (%)
1	36	64
2	36	64
3	36	64
4	36	64
5	36	64
6	36	64
7	36	64
8	37	63
9	37	63
10	37	63
11	37	63
12	38	62
13	38	62
14	38	62
15	39	61
16	39	61
17	40	60
18	41	59
19	42	58
20	43	57
21	43	57
22	44	56
23	45	55
24	46	54
25	46	54
26	47	53
27	47	53
28	47	53
29	48	52
30	48	52

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

	Clearer (%)	Cloudier (%)
1	6	94
2	6	94
3	6	94
4	6	94
5	6	94
6	6	94
7	6	94
8	5	95
9	5	95
10	5	95
11	5	95
12	5	95
13	5	95
14	5	95
15	5	95
16	5	95
17	6	94
18	6	94
19	6	94
20	6	94
21	6	94
22	6	94
23	6	94
24	6	94
25	6	94
26	6	94
27	6	94
28	6	94
29	6	94
30	6	94

	Rain chance (%)
1	92
2	92
3	92
4	92
5	92
6	92
7	93
8	93
9	93
10	93
11	93
12	94
13	94
14	94
15	94
16	94
17	94
18	95
19	95
20	95
21	95
22	95
23	95
24	95
25	95
26	94
27	94
28	94
29	94
30	94

	Oppressive (%)	Miserable (%)
1	36	64
2	36	64
3	36	64
4	36	64
5	36	64
6	36	64
7	36	64
8	37	63
9	37	63
10	37	63
11	37	63
12	38	62
13	38	62
14	38	62
15	39	61
16	39	61
17	40	60
18	41	59
19	42	58
20	43	57
21	43	57
22	44	56
23	45	55
24	46	54
25	46	54
26	47	53
27	47	53
28	47	53
29	48	52
30	48	52