Guapimirim weather in September

In September, Guapimirim sees average daytime highs of 25°C and overnight lows near 16°C, with 102 mm of rain across 12 wet days and about 11.9 hours of daylight. It is the 8th-warmest and 8th-wettest month of the year here.

Day-to-day highs hold fairly steady near 25°C through the month. The sky is clear or mostly clear about 34% of the time in September, and the air most often feels humid.

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 Guapimirim's 5th-clearest and 1st-windiest month. For the whole year in context, see Guapimirim's year-round climate.

Daytime high
25°
8th warmest
Overnight low
16°
5th coldest
Rainfall
102 mm
12 wet days
Daylight
11 h 54 min
6:50 AM – 6:42 PM
Cloud cover
59%
5th clearest
Wind
6 km/h
1st windiest
Solar energy
4.58 kWh/m²
Travel score
6.6
out of 10

Guapimirim is human settlement in Brazil.

Air quality
Good
PM10 16 µg/m³ · 2012

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 25°C through the month.

A typical September day in Guapimirim reaches about 25°C in the afternoon and slips back to 16°C overnight — a 9°C spread between the day's warmth and the night's chill. On most days the high lands between 20°C and 30°C. Set against its neighbours, September runs about 1°C warmer than August and about 1°C cooler than October.

10°15°20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
12516
22516
32516
42516
52516
62516
72516
82516
92516
102516
112516
122516
132516
142516
152516
162517
172517
182517
192517
202517
212517
222517
232517
242517
252517
262517
272517
282517
292517
302517

Guapimirim weather by month

How September compares with the rest of the year at a glance. September is the 8th-warmest and 8th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 21°32823.313.23.8
Feb29° / 21°24218.712.84.0
Mar28° / 20°25922.212.24.3
Apr27° / 19°11915.311.55.7
May24° / 16°8011.410.96.8
Jun24° / 15°497.410.67.6
Jul24° / 14°487.210.87.6
Aug24° / 15°497.511.27.5
Sep25° / 16°1021211.96.6
Oct26° / 18°1501612.55.6
Nov26° / 19°27220.713.14.7
Dec28° / 20°32323.613.44.2

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 34% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 11% of September, with mostly cloudy or overcast conditions the remaining 55%. Skies tend to cloud over as the month goes on.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
16040
26040
35941
45941
55842
65743
75644
85545
95347
105248
115149
124951
134753
144654
154456
164357
174258
184060
193961
203862
213763
223664
233565
243565
253466
263466
273367
283268
293169
303169

Chance of precipitation in September

Any precipitation

Guapimirim gets around 102 mm of rain over 12 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 39% and peaks near 49% on the wettest days. The odds climb toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
129
230
330
431
532
633
733
834
934
1035
1135
1236
1336
1437
1537
1638
1739
1840
1941
2042
2143
2244
2344
2445
2546
2647
2748
2848
2949
3049

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the humid band about 47% of days. Sticky, muggy-or-worse air turns up on roughly 15% of them.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)Humid (%)Muggy (%)
11040455
2939456
3939466
4939467
5838477
6838477
7837478
8736488
9736489
10735499
116354910
126344911
135345011
145335012
154335013
164325014
174325015
184314916
194304917
204304818
214294819
224284720
235274622
245274623
255264624
265254525
275244526
285234527
295224528
305214529

Wind in September

Winds average 6 km/h in September, the windiest month of the year.

Across September, daily wind ranges from about 5 km/h on the calmest days to 6 km/h at its breeziest. It stays fairly steady from day to day.

0246810151015202530
Wind speed (km/h)Feels
16calm
26calm
36calm
46calm
56calm
66calm
76calm
86calm
96calm
106calm
116calm
126calm
136calm
146calm
156calm
166calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
295calm
305calm

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 7:05 AM to 6:36 AM, and sunset from 6:38 PM to 6:47 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.57:056:38
211.67:046:38
311.67:036:39
411.67:026:39
511.67:016:39
611.77:006:39
711.76:596:40
811.76:586:40
911.76:576:40
1011.76:566:41
1111.86:556:41
1211.86:546:41
1311.86:536:42
1411.86:526:42
1511.86:516:42
1611.96:506:42
1711.96:496:43
1811.96:486:43
1911.96:476:43
2012.06:466:44
2112.06:456:44
2212.06:446:44
2312.06:436:45
2412.16:426:45
2512.16:416:45
2612.16:406:45
2712.16:396:46
2812.16:386:46
2912.26:376:46
3012.26:366:47

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.58 kWh/m².

For context, solar energy here swings from a low near 3.39 kWh/m² to a high of 5.92 kWh/m² in February across the year — September's 4.58 kWh/m² falls in the middle.

024151015202530
Solar energy (kWh/m²)Level
14.6Bright
24.6Bright
34.6Bright
44.6Bright
54.6Bright
64.6Bright
74.6Bright
84.6Bright
94.6Bright
104.6Bright
114.6Bright
124.6Bright
134.6Bright
144.6Bright
154.6Bright
164.6Bright
174.6Bright
184.6Bright
194.6Bright
204.6Bright
214.6Bright
224.6Bright
234.6Bright
244.6Bright
254.6Bright
264.6Bright
274.6Bright
284.6Bright
294.6Bright
304.6Bright
Planning a trip in September

Hazard calendar for Guapimirim

In seasonPeak

None of Guapimirim's seasonal hazards are active in September. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do peak.

Guapimirim's rainy season runs October–March, when most of the year's rain falls.

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

Is September a good time to visit Guapimirim?

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

6.6
Sightseeing
5th-best month of the year
5.9
Beach & pool
4th-best month of the year

September is a reasonable time to visit Guapimirim for sightseeing.

What to pack for Guapimirim in September

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

In September, Guapimirim sees daytime highs around 25°C and nights near 16°C. Worth packing: light clothes, rain gear and sun protection. About 12 days see rain.

light clothesrain gearsun protection

Sea temperature near Guapimirim 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 66 km away) is warmest in March at about 25°C and coldest in August 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
Jan25Warm
Feb25Warm
Mar25Warm
Apr25Warm
May24Refreshing
Jun23Refreshing
Jul22Refreshing
Aug21Refreshing
Sep21Refreshing
Oct22Refreshing
Nov23Refreshing
Dec24Warm

UV index in Guapimirim 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 Guapimirim peaks around January 21 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 11 at about 6 (high).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highHighVery highExtremeJan 21UV 14Jul 11UV 6
UV index (midday)Level
Jan15Extreme
Feb14Extreme
Mar13Extreme
Apr10Very high
May7High
Jun6High
Jul6High
Aug8Very high
Sep7Very high
Oct12Extreme
Nov14Extreme
Dec14Extreme

Air quality in Guapimirim 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 Guapimirim is worst in September — around 19 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (March, 10 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodSep 1518 µg/m³Mar 1110 µg/m³
PM2.5 (µg/m³)Level
Jan11Good
Feb11Good
Mar10Good
Apr12Good
May15Moderate
Jun16Moderate
Jul15Moderate
Aug15Moderate
Sep19Moderate
Oct13Moderate
Nov11Good
Dec10Good
Location & terrain

Where is Guapimirim?

Guapimirim sits at 22.5°S, 43.0°W, 33 m above sea level, in Brazil. The nearest listed city is São Pedro, 13 km away.

Topography around Guapimirim

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

Within 3 km, the terrain around Guapimirim has significant variations in elevation — a maximum elevation change of 480 m around an average of 97 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 2,243 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,252 m.

The land around Guapimirim is covered by trees (74%) within 3 km, trees (71%) and grassland (22%) within 16 km, and trees (47%) and grassland (29%) within 80 km.

3 km
480 m
16 km
2,243 m
80 km
2,252 m
treesgrasslandcroplandartificial surfaceswaterwetland
September weather nearby: São Pedro 13 km · Teresópolis 13 km · Magé 14 km · Petrópolis 21 km · Itaboraí 26 km · Cachoeiras de Macacu 35 km · Tanguá 35 km · Niterói 40 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 Guapimirim (-22.5372°, -42.9819°, elevation 33 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).