Cataño weather in September

In September, Cataño sees average daytime highs of 30°C and overnight lows near 25°C, with 131 mm of rain across 20.8 wet days and about 12.1 hours of daylight. It is the 3rd-warmest and 1st-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 24% of the time in September, and the air most often feels miserable.

Daylight stretches from about 12 h 24 min at the start of September to 11 h 54 min by month's end. Set against the rest of the year, September is Cataño's 12th-clearest and 10th-windiest month. For the whole year in context, see Cataño's year-round climate.

Daytime high
30°
3rd warmest
Overnight low
25°
11th coldest
Rainfall
131 mm
20.8 wet days
Daylight
12 h 06 min
6:16 AM – 6:22 PM
Cloud cover
65%
12th clearest
Wind
13 km/h
10th windiest
Solar energy
5.81 kWh/m²
Travel score
3.7
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 Cataño reaches about 30°C in the afternoon and slips back to 25°C overnight — a 5°C spread between the day's warmth and the night's chill. On most days the high lands between 29°C and 31°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
93025
103025
113025
123025
133025
143025
153025
163025
173025
183025
193025
203025
213025
223025
233025
243025
253025
263025
273025
283025
293025
303025

How September really feels in Cataño

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.

Cataño weather by month

How September compares with the rest of the year at a glance. September is the 3rd-warmest and 1st-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan27° / 23°3910.4116.8
Feb27° / 22°287.611.47.1
Mar28° / 23°398.411.96.9
Apr28° / 23°721112.45.8
May29° / 24°11216.212.94.7
Jun30° / 25°6813.913.14.5
Jul30° / 25°8016.5134.4
Aug30° / 25°9518.712.64.0
Sep30° / 25°13120.812.13.7
Oct29° / 25°12520.511.64.0
Nov28° / 24°11218.211.14.9
Dec27° / 23°4812.210.96.4

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 24% of the time in September, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 21% of September, with mostly cloudy or overcast conditions the remaining 56%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
14753
24753
34753
44753
54753
64852
74852
84852
94753
104753
114654
124654
134555
144456
154456
164357
174357
184357
194258
204159
214159
224159
234159
244258
254159
264258
274357
284357
294456
304456

Chance of precipitation in September

Any precipitation

Cataño gets around 131 mm of rain over 20.8 wet days in September, the wettest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 69% and peaks near 73% on the wettest days.

0%20%40%60%80%151015202530
Rain chance (%)
167
267
367
466
566
666
765
865
966
1066
1166
1267
1368
1468
1569
1670
1771
1871
1972
2073
2173
2273
2373
2473
2572
2672
2771
2871
2970
3070

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 52% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Oppressive (%)Miserable (%)
14357
24357
34456
44456
54456
64555
74555
84555
94654
104654
114753
124753
134852
144852
154852
164852
174951
184951
194951
204951
215050
225050
235149
245149
255248
265248
275347
285446
295545
305644

Wind in September

Winds average 13 km/h in September.

Across September, daily wind ranges from about 12 km/h on the calmest days to 14 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
114light breeze
214light breeze
314light breeze
413light breeze
513light breeze
613light breeze
713light breeze
813light breeze
913light breeze
1013light breeze
1113light breeze
1213light breeze
1313light breeze
1413light breeze
1513light breeze
1613light breeze
1713light breeze
1813light breeze
1913light breeze
2012light breeze
2112light breeze
2212light breeze
2312light breeze
2412light breeze
2512light breeze
2612light breeze
2712light breeze
2812light breeze
2912calm
3012calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 24 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 30 minutes over September. Sunrise moves from 6:13 AM to 6:18 AM, and sunset from 6:35 PM to 6:09 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.46:136:35
212.36:136:34
312.36:146:33
412.36:146:33
512.36:146:32
612.36:146:31
712.36:146:30
812.26:146:29
912.26:156:28
1012.26:156:27
1112.26:156:26
1212.26:156:26
1312.26:156:25
1412.16:156:24
1512.16:166:23
1612.16:166:22
1712.16:166:21
1812.16:166:20
1912.06:166:19
2012.06:166:18
2112.06:176:17
2212.06:176:16
2312.06:176:16
2412.06:176:15
2511.96:176:14
2611.96:176:13
2711.96:186:12
2811.96:186:11
2911.96:186:10
3011.96:186:09

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.81 kWh/m².

For context, solar energy here swings from a low near 4.34 kWh/m² to a high of 6.56 kWh/m² in June across the year — September's 5.81 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
16.1Intense
26.1Intense
36.1Intense
46.1Intense
56.0Intense
66.0Intense
76.0Intense
86.0Bright
96.0Bright
106.0Bright
115.9Bright
125.9Bright
135.9Bright
145.8Bright
155.8Bright
165.8Bright
175.8Bright
185.8Bright
195.7Bright
205.7Bright
215.7Bright
225.7Bright
235.6Bright
245.6Bright
255.6Bright
265.6Bright
275.6Bright
285.5Bright
295.5Bright
305.5Bright
Planning a trip in September

Hazard calendar for Cataño

In seasonPeak

In September, Cataño sits inside its atlantic hurricane season. The full year is below, with each hazard's peak months called out.

Cataño sits in the Atlantic hurricane belt; the season peaks August–October.

Cataño sees seasonal dust haze (July), heaviest in July.

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

Is September a good time to visit Cataño?

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

3.7
Sightseeing
12th-best month of the year
5.1
Beach & pool
12th-best month of the year

September is a weaker month for outdoor sightseeing in Cataño.

What to pack for Cataño in September

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

In September, Cataño sees daytime highs around 30°C and nights near 25°C. Pack light clothes and rain gear. Worth having: sun protection. About 21 days see rain.

light clothesrain gearsun protection

Sea temperature near Cataño in September

The nearest coast averages about 29°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 20 km away) is warmest in September at about 29°C and coldest in February near 26°C.

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

24°26°28°30°JanFebMarAprMayJunJulAugSepOctNovDecwarmtropicalcomfortable to swim
Sea temperature (°C)Comfort
Jan27Warm
Feb26Warm
Mar26Warm
Apr27Warm
May27Warm
Jun28Warm
Jul28Tropical
Aug29Tropical
Sep29Tropical
Oct29Tropical
Nov28Tropical
Dec27Warm

UV index in Cataño 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 Cataño peaks around April 13 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near December 16 at about 7 (high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecVery highExtremeVery highApr 13UV 13Dec 16UV 7
UV index (midday)Level
Jan8Very high
Feb10Extreme
Mar12Extreme
Apr13Extreme
May11Extreme
Jun12Extreme
Jul12Extreme
Aug12Extreme
Sep12Extreme
Oct10Very high
Nov8Very high
Dec7High

Air quality in Cataño 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 Cataño is worst in July — around 24 µg/m³ PM2.5 (moderate), about 4.6× the cleanest month (January, 5 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJul 1324 µg/m³Jan 15 µg/m³
PM2.5 (µg/m³)Level
Jan5Good
Feb7Good
Mar7Good
Apr8Good
May14Moderate
Jun23Moderate
Jul24Moderate
Aug20Moderate
Sep15Moderate
Oct15Moderate
Nov8Good
Dec5Good
Location & terrain

Where is Cataño?

Cataño sits at 18.4°N, 66.1°W, 3 m above sea level, in Puerto Rico. The nearest listed city is San Juan, 3.0 km away.

CarolinaCaguas

Topography around Cataño

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

Within 3 km, the terrain around Cataño has only modest variations in elevation — a maximum elevation change of 77 m around an average of 4 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 326 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,308 m.

The land around Cataño is covered by water (40%) and artificial surfaces (35%) within 3 km, water (45%), artificial surfaces (25%) and trees (24%) within 16 km, and water (59%) and trees (32%) within 80 km.

3 km
77 m
16 km
326 m
80 km
1,308 m
treesgrasslandartificial surfacesbare terrainwaterwetlandmangroves
September weather nearby: San Juan 3.0 km · Bayamón 6.0 km · Levittown 7.0 km · Guaynabo 9.0 km · Candelaria 10 km · Trujillo Alto 15 km · Carolina 18 km · Caguas 24 km

Puerto Rico travel facts

Power plugs
Type A / B
120 V · 60 Hz
Prices
≈ 78% of US
price level, 2025
GDP per capita
$40,620
2025
Happiness
7.0 / 10
World Happiness, 2015
Safe drinking water
99%
of population, 2024
Homicide rate
14.6
per 100k, 2023
Income group
High
World Bank
Religion
Roman Catholic 56%Protestant 33%none 7%other 2%

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 Cataño (18.4413°, -66.1182°, elevation 3 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. Tropical-cyclone seasons are the published climatological basin seasons (NOAA National Hurricane Center / regional warning centres). 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).