Cabo Frio weather in September

In September, Cabo Frio sees average daytime highs of 22°C and overnight lows near 21°C, with 47 mm of rain across 7.1 wet days and about 11.9 hours of daylight. It is the 11th-warmest and 9th-wettest month of the year here.

Day-to-day highs hold fairly steady near 22°C through the month. The sky is clear or mostly clear about 50% of the time in September, and the air most often feels muggy.

Daylight stretches from about 11 h 30 min at the start of September to 12 h 12 min by month's end. Set against the rest of the year, September is Cabo Frio's 6th-clearest and 1st-windiest month. For the whole year in context, see Cabo Frio's year-round climate.

Daytime high
22°
11th warmest
Overnight low
21°
3rd coldest
Rainfall
47 mm
7.1 wet days
Daylight
11 h 54 min
6:46 AM – 6:39 PM
Cloud cover
46%
6th clearest
Wind
26 km/h
1st windiest
Solar energy
5.2 kWh/m²
Travel score
7.4
out of 10

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 22°C through the month.

A typical September day in Cabo Frio reaches about 22°C in the afternoon and slips back to 21°C overnight — a 1°C spread between the day's warmth and the night's chill. On most days the high lands between 21°C and 24°C. Set against its neighbours, September runs on par with August and on par with October.

15°18°20°23°25°151015202530
Avg high (°C)Avg low (°C)
12221
22221
32221
42221
52221
62221
72221
82221
92221
102221
112221
122221
132221
142221
152221
162221
172221
182221
192221
202221
212221
222221
232221
242221
252221
262221
272221
282221
292221
302221

Cabo Frio weather by month

How September compares with the rest of the year at a glance. September is the 11th-warmest and 9th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan25° / 24°888.313.27.1
Feb26° / 24°52612.87.3
Mar26° / 24°1051112.26.7
Apr25° / 24°579.511.57.2
May24° / 22°5810.110.97.3
Jun23° / 21°346.410.67.8
Jul22° / 21°356.610.77.7
Aug22° / 21°286.111.27.7
Sep22° / 21°477.111.97.4
Oct23° / 21°547.712.57.2
Nov24° / 22°10110.613.16.7
Dec25° / 23°969.713.46.9

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 50% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 12% of September, with mostly cloudy or overcast conditions the remaining 38%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
17426
27426
37327
47327
57228
67129
77030
86931
96733
106733
116535
126337
136337
146238
156040
165941
175941
185842
195743
205644
215644
225545
235446
245446
255347
265347
275446
285347
295347
305347

Chance of precipitation in September

Any precipitation

Cabo Frio gets around 47 mm of rain over 7.1 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 23% and peaks near 26% on the wettest days. The odds climb toward the end of the month.

0%10%20%30%40%151015202530
Rain chance (%)
118
219
319
419
519
620
720
820
921
1021
1121
1222
1322
1422
1523
1623
1724
1824
1925
2025
2125
2226
2326
2426
2526
2626
2726
2826
2926
3026

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the muggy band about 56% of days. Sticky, muggy-or-worse air turns up on roughly 60% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)Oppressive (%)
141326561
241326561
341326561
441326561
541325571
641225581
741225581
841225581
941225581
1031225582
1131225582
1231225582
1331225582
1421125602
1521125593
1621125593
1721125593
1831124593
1931124584
2031124584
2131225555
2231225555
2341225536
2441225536
2541125537
2641125528
2741125528
2841125519
29411255010
30411255010

Wind in September

Winds average 26 km/h in September, the windiest month of the year.

Across September, daily wind ranges from about 25 km/h on the calmest days to 27 km/h at its breeziest. It stays fairly steady from day to day.

0102030151015202530
Wind speed (km/h)Feels
126breezy
226breezy
326breezy
426breezy
526breezy
626breezy
726breezy
827breezy
927breezy
1027breezy
1127breezy
1227breezy
1327breezy
1427breezy
1527breezy
1627breezy
1726breezy
1826breezy
1926breezy
2026breezy
2126breezy
2226breezy
2326breezy
2425breezy
2525breezy
2625breezy
2725breezy
2825breezy
2925breezy
3025breezy

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 h 30 min at the start of September to 12 h 12 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 42 minutes over September. Sunrise moves from 7:02 AM to 6:32 AM, and sunset from 6:34 PM to 6:43 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.57:026:34
211.67:016:34
311.67:006:35
411.66:596:35
511.66:586:35
611.66:576:35
711.76:566:36
811.76:556:36
911.76:546:36
1011.76:536:37
1111.86:526:37
1211.86:516:37
1311.86:496:38
1411.86:486:38
1511.86:476:38
1611.96:466:39
1711.96:456:39
1811.96:446:39
1911.96:436:39
2012.06:426:40
2112.06:416:40
2212.06:406:40
2312.06:396:41
2412.16:386:41
2512.16:376:41
2612.16:366:42
2712.16:356:42
2812.16:346:42
2912.26:336:43
3012.26:326:43

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.2 kWh/m².

For context, solar energy here swings from a low near 3.58 kWh/m² to a high of 6.65 kWh/m² in February across the year — September's 5.2 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
15.0Bright
25.0Bright
35.0Bright
45.0Bright
55.1Bright
65.1Bright
75.1Bright
85.1Bright
95.1Bright
105.2Bright
115.2Bright
125.2Bright
135.2Bright
145.2Bright
155.2Bright
165.2Bright
175.3Bright
185.3Bright
195.3Bright
205.3Bright
215.3Bright
225.3Bright
235.3Bright
245.3Bright
255.4Bright
265.4Bright
275.4Bright
285.4Bright
295.5Bright
305.5Bright
Planning a trip in September

Is September a good time to visit Cabo Frio?

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

7.4
Sightseeing
4th-best month of the year
5.2
Beach & pool
12th-best month of the year

September is one of the better times to visit Cabo Frio for general sightseeing.

What to pack for Cabo Frio in September

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

In September, Cabo Frio sees daytime highs around 22°C and nights near 21°C. Worth packing: light clothes, sun protection and a windbreaker. About 7 days see rain.

light clothessun protectiona windbreaker

Sea temperature near Cabo Frio in September

The nearest coast averages about 21°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 March at about 25°C and coldest in September near 21°C.

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

20°22°24°26°JanFebMarAprMayJunJulAugSepOctNovDeccoolrefreshingwarmcomfortable to swim
Sea temperature (°C)Comfort
Jan24Warm
Feb24Warm
Mar25Warm
Apr25Warm
May24Refreshing
Jun23Refreshing
Jul22Refreshing
Aug22Refreshing
Sep21Refreshing
Oct22Refreshing
Nov23Refreshing
Dec24Refreshing

UV index in Cabo Frio in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 7 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Cabo Frio peaks around January 15 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 12 at about 5 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highHighVery highExtremeJan 15UV 14Jul 12UV 5
UV index (midday)Level
Jan14Extreme
Feb13Extreme
Mar12Extreme
Apr9Very high
May7High
Jun6High
Jul5High
Aug8Very high
Sep7High
Oct11Extreme
Nov13Extreme
Dec13Extreme
Location & terrain

Where is Cabo Frio?

Cabo Frio sits at 22.9°S, 42.0°W, 13 m above sea level, in Brazil. The nearest listed city is Arraial do Cabo, 9.0 km away.

Topography around Cabo Frio

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

Within 3 km, the terrain around Cabo Frio has only modest variations in elevation — a maximum elevation change of 100 m around an average of 5 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 375 m; within 80 km, very significant variations in elevation — a maximum elevation change of 1,806 m.

The land around Cabo Frio is covered by water (44%) and artificial surfaces (35%) within 3 km, water (61%) within 16 km, and water (51%), trees (26%) and grassland (20%) within 80 km.

3 km
100 m
16 km
375 m
80 km
1,806 m
treesgrasslandartificial surfacesbare terrainwaterwetland
September weather nearby: Arraial do Cabo 9.0 km · São Pedro da Aldeia 9.0 km · Iguaba Grande 21 km · Buzios 22 km · Araruama 33 km · Rio das Ostras 41 km · Saquarema 45 km · Silva Jardim 46 km

Brazil travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / N
127 / 220 V · 60 Hz
Prices
≈ 46% of US
price level, 2025
GDP per capita
$10,713
2025
Happiness
6.6 / 10
World Happiness, 2025
Safe drinking water
89%
of population, 2024
Homicide rate
19.3
per 100k, 2023
Road deaths
16
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Low
EF EPI 482
Religion
Roman Catholic 57%Evangelical 27%none 9%other 4%

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 Cabo Frio (-22.8872°, -42.0262°, elevation 13 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).