Santiago de Tolú weather in September

In September, Santiago de Tolú sees average daytime highs of 30°C and overnight lows near 24°C, with 240 mm of rain across 29.1 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 30°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 Santiago de Tolú's 10th-clearest and 8th-windiest month. For the whole year in context, see Santiago de Tolú's year-round climate.

Daytime high
30°
10th warmest
Overnight low
24°
5th coldest
Rainfall
240 mm
29.1 wet days
Daylight
12 h 06 min
5:55 AM – 5:58 PM
Cloud cover
91%
10th clearest
Wind
7 km/h
8th windiest
Solar energy
4.91 kWh/m²
Travel score
2.5
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 30°C through the month.

A typical September day in Santiago de Tolú reaches about 30°C in the afternoon and slips back to 24°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 28°C and 32°C. Set against its neighbours, September runs on par with August and on par with October.

20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
13025
23025
33025
43025
53025
63025
73025
83025
93024
103024
113024
123024
133024
143024
153024
163024
173024
183024
193024
203024
213024
223024
233024
243024
253024
263024
273024
283024
293024
303024

How September really feels in Santiago de Tolú

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
30
heat index over the day's high
Days feeling ≤ C
0
wind chill below the day's low

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

Santiago de Tolú 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.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan32° / 24°277.811.54.6
Feb32° / 25°317.811.74.2
Mar32° / 25°6615.511.93.5
Apr31° / 25°16725.612.22.7
May31° / 25°26329.512.42.4
Jun31° / 25°24928.112.52.4
Jul31° / 25°2282812.52.5
Aug31° / 25°2392912.32.5
Sep30° / 24°24029.112.12.5
Oct30° / 24°24029.811.82.6
Nov30° / 24°18027.211.62.8
Dec31° / 24°871811.53.7

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 4% of September, with mostly cloudy or overcast conditions the remaining 96%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
1496
2595
3595
4595
5595
6595
7496
8496
9496
10496
11496
12496
13496
14496
15496
16496
17496
18595
19595
20595
21595
22595
23595
24595
25595
26595
27595
28496
29496
30496

Chance of precipitation in September

Any precipitation

Santiago de Tolú gets around 240 mm of rain over 29.1 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 97% and peaks near 98% on the wettest days.

0%20%40%60%80%100%151015202530
Rain chance (%)
196
296
396
496
596
696
797
897
997
1097
1197
1297
1397
1498
1598
1698
1798
1898
1998
2098
2197
2297
2397
2497
2597
2697
2797
2897
2997
3097

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 78% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
11882
21882
31882
41882
51882
61981
71981
82080
92080
102080
112179
122179
132179
142278
152278
162377
172377
182476
192476
202575
212575
222674
232674
242674
252674
262674
272674
282674
292674
302674

Wind in September

Winds average 7 km/h in September.

Across September, daily wind ranges from about 7 km/h on the calmest days to 7 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
17calm
27calm
37calm
47calm
57calm
67calm
77calm
87calm
97calm
107calm
117calm
127calm
137calm
147calm
157calm
167calm
177calm
187calm
197calm
207calm
217calm
227calm
237calm
247calm
257calm
267calm
277calm
287calm
297calm
307calm

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 6:08 PM to 5:49 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.25:566:08
212.25:566:07
312.25:566:06
412.25:566:06
512.15:566:05
612.15:566:05
712.15:566:04
812.15:566:03
912.15:566:03
1012.15:566:02
1112.15:566:01
1212.15:566:01
1312.15:556:00
1412.15:555:59
1512.15:555:59
1612.15:555:58
1712.05:555:58
1812.05:555:57
1912.05:555:56
2012.05:555:56
2112.05:555:55
2212.05:545:54
2312.05:545:54
2412.05:545:53
2512.05:545:52
2612.05:545:52
2712.05:545:51
2811.95:545:51
2911.95:545:50
3011.95:545:49

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.91 kWh/m².

For context, solar energy here swings from a low near 4.49 kWh/m² to a high of 5.9 kWh/m² in March across the year — September's 4.91 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.0Bright
25.0Bright
35.0Bright
45.0Bright
55.0Bright
65.0Bright
75.0Bright
85.0Bright
95.0Bright
105.0Bright
115.0Bright
125.0Bright
135.0Bright
144.9Bright
154.9Bright
164.9Bright
174.9Bright
184.9Bright
194.9Bright
204.9Bright
214.9Bright
224.8Bright
234.8Bright
244.8Bright
254.8Bright
264.8Bright
274.8Bright
284.8Bright
294.8Bright
304.8Bright
Planning a trip in September

Is September a good time to visit Santiago de Tolú?

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

2.5
Sightseeing
8th-best month of the year
3.5
Beach & pool
12th-best month of the year

September is a weaker month for outdoor sightseeing in Santiago de Tolú.

What to pack for Santiago de Tolú in September

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

In September, Santiago de Tolú sees daytime highs around 30°C and nights near 24°C. Pack light clothes and rain gear. Worth having: sun protection. About 29 days see rain.

light clothesrain gearsun protection

Sea temperature near Santiago de Tolú 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 offshore 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.

26°28°30°32°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan29Tropical
Feb28Tropical
Mar28Tropical
Apr29Tropical
May29Tropical
Jun30Tropical
Jul30Tropical
Aug30Tropical
Sep30Tropical
Oct29Tropical
Nov29Tropical
Dec29Tropical

UV index in Santiago de Tolú 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 Santiago de Tolú 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.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highJun 10UV 13Dec 13UV 10
UV index (midday)Level
Jan11Extreme
Feb12Extreme
Mar12Extreme
Apr12Extreme
May13Extreme
Jun13Extreme
Jul11Extreme
Aug12Extreme
Sep12Extreme
Oct12Extreme
Nov10Very high
Dec10Very high

Air quality in Santiago de Tolú 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 Santiago de Tolú 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).

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateMar 2325 µg/m³Nov 1111 µg/m³
PM2.5 (µg/m³)Level
Jan14Moderate
Feb18Moderate
Mar26Moderate
Apr25Moderate
May25Moderate
Jun23Moderate
Jul26Moderate
Aug20Moderate
Sep14Moderate
Oct12Good
Nov11Good
Dec14Moderate
Location & terrain

Where is Santiago de Tolú?

Santiago de Tolú sits at 9.5°N, 75.6°W, 10 m above sea level, in Colombia. The nearest listed city is Tolú Viejo, 18 km away.

Topography around Santiago de Tolú

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Santiago de Tolú.

Within 3 km, the terrain around Santiago de Tolú has only modest variations in elevation — a maximum elevation change of 19 m around an average of 4 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 156 m; within 80 km, large variations in elevation — a maximum elevation change of 810 m.

The land around Santiago de Tolú is covered by grassland (44%) and water (42%) within 3 km, grassland (43%) and water (43%) within 16 km, and grassland (47%), water (28%) and trees (20%) within 80 km.

3 km
19 m
16 km
156 m
80 km
810 m
treesgrasslandartificial surfaceswaterwetlandmangroves
September weather nearby: Tolú Viejo 18 km · San Onofre 24 km · San Antero 26 km · Sincelejo 32 km · Momil 33 km · Corozal 39 km · Lorica 41 km · Sampués 44 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
Roman Catholic 64%Protestant 17%none 14%atheist 1%

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 Santiago de Tolú (9.5239°, -75.5814°, elevation 10 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).