Boa Vista weather in September

In September, Boa Vista sees average daytime highs of 32°C and overnight lows near 24°C, with 94 mm of rain across 15.4 wet days and about 12 hours of daylight. It is the 7th-warmest and 6th-wettest month of the year here.

Day-to-day highs hold fairly steady near 32°C through the month. The sky is clear or mostly clear about 39% of the time in September, and the air most often feels oppressive.

Daylight stretches from about 12 h 06 min at the start of September to 12 hours by month's end. Set against the rest of the year, September is Boa Vista's 1st-clearest and 9th-windiest month. For the whole year in context, see Boa Vista's year-round climate.

Daytime high
32°
7th warmest
Overnight low
24°
5th coldest
Rainfall
94 mm
15.4 wet days
Daylight
12 hours
5:57 AM – 5:57 PM
Cloud cover
53%
1st clearest
Wind
5 km/h
9th windiest
Solar energy
5.64 kWh/m²
Travel score
3.5
out of 10

Boa Vista is human settlement in Brazil, Roraima.

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 32°C through the month.

A typical September day in Boa Vista reaches about 32°C in the afternoon and slips back to 24°C overnight — a 8°C spread between the day's warmth and the night's chill. On most days the high lands between 30°C and 34°C. Set against its neighbours, September runs about 2°C warmer than August and about 1°C cooler than October.

20°25°30°35°151015202530
Avg high (°C)Avg low (°C)
13224
23224
33224
43224
53224
63224
73224
83224
93224
103224
113224
123224
133224
143224
153224
163224
173224
183224
193224
203224
213224
223224
233224
243324
253324
263324
273324
283324
293324
303324

How September really feels in Boa Vista

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.

Boa Vista weather by month

How September compares with the rest of the year at a glance. September is the 7th-warmest and 6th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan33° / 24°346.711.93.8
Feb33° / 25°315.711.93.6
Mar33° / 25°599.2123.2
Apr32° / 24°20017.412.13.1
May30° / 24°34426.412.13.0
Jun29° / 23°31027.312.23.1
Jul29° / 23°24926.712.13.3
Aug31° / 23°15622.312.13.4
Sep32° / 24°9415.4123.5
Oct33° / 24°7112.811.93.3
Nov33° / 24°9013.611.93.2
Dec32° / 24°5810.211.83.7

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 39% of the time in September, the clearest month of the year.

Beyond those clear spells, partly cloudy skies cover about 22% of September, with mostly cloudy or overcast conditions the remaining 39%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15941
26040
36040
46139
56040
66040
76139
86040
96139
106040
116139
126139
136139
146040
156040
166040
176139
186139
196139
206139
216139
226139
236139
246238
256238
266238
276238
286238
296238
306139

Chance of precipitation in September

Any precipitation

Boa Vista gets around 94 mm of rain over 15.4 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 51% and peaks near 60% on the wettest days. The odds ease toward the end of the month.

0%20%40%60%151015202530
Rain chance (%)
160
259
358
458
558
657
757
857
956
1056
1156
1255
1354
1453
1552
1652
1751
1850
1949
2048
2147
2246
2345
2444
2543
2642
2741
2841
2940
3040

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the oppressive band about 58% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

0%25%50%75%100%151015202530
Muggy (%)Oppressive (%)Miserable (%)
105842
205842
305842
405842
515742
615742
715742
815742
915742
1015742
1115742
1225741
1325741
1425741
1525741
1625741
1725741
1835641
1935740
2035740
2145640
2245739
2345838
2455738
2555837
2655936
2765935
2866034
2976033
3076132

Wind in September

Winds average 5 km/h in September.

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
15calm
25calm
35calm
45calm
55calm
65calm
75calm
85calm
95calm
105calm
115calm
125calm
135calm
145calm
155calm
165calm
176calm
186calm
196calm
206calm
216calm
226calm
236calm
246calm
256calm
266calm
276calm
286calm
296calm
306calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 12 h 06 min at the start of September to 12 hours by month's end. The lit band spans sunrise to sunset each day.

Days shrink by about 6 minutes over September. Sunrise moves from 6:01 AM to 5:53 AM, and sunset from 6:04 PM to 5:51 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
112.16:016:04
212.16:016:04
312.06:006:03
412.06:006:03
512.06:006:02
612.05:596:02
712.05:596:01
812.05:596:01
912.05:596:01
1012.05:586:00
1112.05:586:00
1212.05:585:59
1312.05:575:59
1412.05:575:58
1512.05:575:58
1612.05:575:57
1712.05:565:57
1812.05:565:57
1912.05:565:56
2012.05:555:56
2112.05:555:55
2212.05:555:55
2312.05:555:54
2412.05:545:54
2512.05:545:53
2612.05:545:53
2712.05:535:53
2812.05:535:52
2912.05:535:52
3012.05:535:51

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.64 kWh/m².

For context, solar energy here swings from a low near 3.8 kWh/m² to a high of 5.72 kWh/m² in October across the year — September's 5.64 kWh/m² sits near the top of that range.

0246151015202530
Solar energy (kWh/m²)Level
15.4Bright
25.4Bright
35.4Bright
45.5Bright
55.5Bright
65.5Bright
75.5Bright
85.5Bright
95.5Bright
105.5Bright
115.6Bright
125.6Bright
135.6Bright
145.6Bright
155.6Bright
165.6Bright
175.7Bright
185.7Bright
195.7Bright
205.7Bright
215.7Bright
225.7Bright
235.7Bright
245.8Bright
255.8Bright
265.8Bright
275.8Bright
285.8Bright
295.8Bright
305.8Bright
Planning a trip in September

Hazard calendar for Boa Vista

In seasonPeak

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

Boa Vista's monsoon runs April–August, when most of the year's rain falls.

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

Is September a good time to visit Boa Vista?

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

3.5
Sightseeing
4th-best month of the year
5.7
Beach & pool
6th-best month of the year

September is a weaker month for outdoor sightseeing in Boa Vista.

What to pack for Boa Vista in September

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

In September, Boa Vista sees daytime highs around 32°C and nights near 24°C. Pack light clothes and rain gear. Worth having: sun protection. About 15 days see rain.

light clothesrain gearsun protection

UV index in Boa Vista 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 Boa Vista peaks around March 20 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near November 17 at about 11 (extreme).

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

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeMar 20UV 15Nov 17UV 11
UV index (midday)Level
Jan14Extreme
Feb13Extreme
Mar15Extreme
Apr14Extreme
May13Extreme
Jun12Extreme
Jul11Extreme
Aug12Extreme
Sep12Extreme
Oct12Extreme
Nov11Extreme
Dec11Extreme

Air quality in Boa Vista 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 Boa Vista is worst in March — around 23 µg/m³ PM2.5 (moderate), about 1.9× the cleanest month (August, 12 µg/m³).

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

0102030JanFebMarAprMayJunJulAugSepOctNovDecModerateGoodModerateMar 2222 µg/m³Aug 2212 µg/m³
PM2.5 (µg/m³)Level
Jan15Moderate
Feb19Moderate
Mar23Moderate
Apr22Moderate
May15Moderate
Jun13Moderate
Jul12Moderate
Aug12Good
Sep12Good
Oct13Moderate
Nov13Moderate
Dec13Moderate
Location & terrain

Where is Boa Vista?

Boa Vista sits at 2.8°N, 60.7°W, 82 m above sea level, in Brazil. The nearest listed city is Cantá, 25 km away.

Topography around Boa Vista

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

Within 3 km, the terrain around Boa Vista has only modest variations in elevation — a maximum elevation change of 29 m around an average of 75 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 130 m; within 80 km, large variations in elevation — a maximum elevation change of 1,011 m.

The land around Boa Vista is covered by artificial surfaces (50%) within 3 km, grassland (67%) within 16 km, and grassland (56%) and trees (41%) within 80 km.

3 km
29 m
16 km
130 m
80 km
1,011 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwaterwetland
September weather nearby: Cantá 25 km · Mucajaí 50 km · Alto Alegre 92 km · Lethem 115 km · Caracaraí 123 km · Pacaraima 187 km · Santa Elena de Uairén 204 km · Rorainópolis 210 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 Boa Vista (2.8197°, -60.6733°, elevation 82 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. 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).