Fonte Boa weather in September

In September, Fonte Boa sees average daytime highs of 31°C and overnight lows near 24°C, with 151 mm of rain across 23.4 wet days and about 12 hours of daylight. It is the 2nd-warmest and 11th-wettest month of the year here.

Day-to-day highs hold fairly steady near 31°C through the month. The sky is clear or mostly clear about 10% of the time in September, and the air most often feels miserable.

Daylight stretches from about 12 hours at the start of September to 12 hours by month's end. Set against the rest of the year, September is Fonte Boa's 3rd-clearest and 10th-windiest month. For the whole year in context, see Fonte Boa's year-round climate.

Daytime high: 31°; 2nd warmest
Overnight low: 24°; 6th coldest
Rainfall: 151 mm; 23.4 wet days
Daylight: 12 hours; 6:19 AM – 6:18 PM
Cloud cover: 71%; 3rd clearest
Wind: 4 km/h; 10th windiest
Solar energy: 5.16 kWh/m²
Travel score: 3.0; out of 10

Fonte Boa is human settlement in Brazil.

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

← August Fonte Boa year-round climate October →Best places to visit in September

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 31°C through the month.

A typical September day in Fonte Boa reaches about 31°C in the afternoon and slips back to 24°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 29°C and 33°C. Set against its neighbours, September runs on par with August and on par with October.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Avg high (°C)	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31
Avg low (°C)	24	24	24	24	24	24	24	24	24	24	24	24	24	24	24	24	24	24	24	24	24	24	24	24	24	24	24	24	24	24

	Avg high (°C)	Avg low (°C)
1	31	24
2	31	24
3	31	24
4	31	24
5	31	24
6	31	24
7	31	24
8	31	24
9	31	24
10	31	24
11	31	24
12	31	24
13	31	24
14	31	24
15	31	24
16	31	24
17	31	24
18	31	24
19	31	24
20	31	24
21	31	24
22	31	24
23	31	24
24	31	24
25	31	24
26	31	24
27	31	24
28	31	24
29	31	24
30	31	24

How September really feels in Fonte Boa

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

6 feel dangerously hot (≥ 39°C)

Days feeling ≤ 0°C

wind chill below the day's low

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

Fonte Boa weather by month

How September compares with the rest of the year at a glance. September is the 2nd-warmest and 11th-wettest month here — the current month is highlighted below.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Daylight (hours)	Travel score
Jan	30° / 24°	273	26.8	12.1	2.8
Feb	30° / 24°	269	23.8	12.1	2.8
Mar	30° / 24°	316	28.4	12	2.7
Apr	30° / 24°	342	27.8	11.9	2.7
May	30° / 24°	352	29.4	11.9	2.8
Jun	29° / 23°	239	27.2	11.9	3.1
Jul	30° / 23°	168	25.3	11.9	3.4
Aug	31° / 23°	136	23.3	11.9	3.3
Sep	31° / 24°	151	23.4	12	3.0
Oct	31° / 24°	175	24.7	12.1	2.8
Nov	31° / 24°	205	25.5	12.1	2.7
Dec	31° / 24°	264	28.5	12.1	2.6

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 10% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 20% of September, with mostly cloudy or overcast conditions the remaining 70%.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Clearer (%)	34	33	33	33	32	32	32	31	31	31	30	30	30	31	30	30	30	30	30	29	30	30	29	29	29	28	28	27	27	26
Cloudier (%)	66	67	67	67	68	68	68	69	69	69	70	70	70	69	70	70	70	70	70	71	70	70	71	71	71	72	72	73	73	74

	Clearer (%)	Cloudier (%)
1	34	66
2	33	67
3	33	67
4	33	67
5	32	68
6	32	68
7	32	68
8	31	69
9	31	69
10	31	69
11	30	70
12	30	70
13	30	70
14	31	69
15	30	70
16	30	70
17	30	70
18	30	70
19	30	70
20	29	71
21	30	70
22	30	70
23	29	71
24	29	71
25	29	71
26	28	72
27	28	72
28	27	73
29	27	73
30	26	74

Chance of precipitation in September

Any precipitation

Fonte Boa gets around 151 mm of rain over 23.4 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 78% and peaks near 78% on the wettest days.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Rain chance (%)	78	78	78	78	78	78	77	77	77	77	77	77	77	77	77	78	78	78	78	78	78	78	78	78	77	77	77	77	77	77

	Rain chance (%)
1	78
2	78
3	78
4	78
5	78
6	78
7	77
8	77
9	77
10	77
11	77
12	77
13	77
14	77
15	77
16	78
17	78
18	78
19	78
20	78
21	78
22	78
23	78
24	78
25	77
26	77
27	77
28	77
29	77
30	77

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 86% of days. Sticky, muggy-or-worse air turns up on roughly 100% of them.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Oppressive (%)	18	18	18	18	18	17	17	17	17	17	16	16	16	15	15	14	14	13	13	13	12	12	12	12	11	11	11	11	11	11
Miserable (%)	82	82	82	82	82	83	83	83	83	83	84	84	84	85	85	86	86	87	87	87	88	88	88	88	89	89	89	89	89	89

	Oppressive (%)	Miserable (%)
1	18	82
2	18	82
3	18	82
4	18	82
5	18	82
6	17	83
7	17	83
8	17	83
9	17	83
10	17	83
11	16	84
12	16	84
13	16	84
14	15	85
15	15	85
16	14	86
17	14	86
18	13	87
19	13	87
20	13	87
21	12	88
22	12	88
23	12	88
24	12	88
25	11	89
26	11	89
27	11	89
28	11	89
29	11	89
30	11	89

Wind in September

Winds average 4 km/h in September.

Across September, daily wind ranges from about 4 km/h on the calmest days to 4 km/h at its breeziest. It stays fairly steady from day to day.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Wind speed (km/h)	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4	4
Feels	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm	calm

	Wind speed (km/h)	Feels
1	4	calm
2	4	calm
3	4	calm
4	4	calm
5	4	calm
6	4	calm
7	4	calm
8	4	calm
9	4	calm
10	4	calm
11	4	calm
12	4	calm
13	4	calm
14	4	calm
15	4	calm
16	4	calm
17	4	calm
18	4	calm
19	4	calm
20	4	calm
21	4	calm
22	4	calm
23	4	calm
24	4	calm
25	4	calm
26	4	calm
27	4	calm
28	4	calm
29	4	calm
30	4	calm

Sunrise & sunset in September

DaylightNight

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

Days grow by about 0 minutes over September. Sunrise moves from 6:26 AM to 6:13 AM, and sunset from 6:23 PM to 6:14 PM.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Daylight (h)	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0
Sunrise (AM)	6:26	6:25	6:25	6:24	6:24	6:23	6:23	6:23	6:22	6:22	6:21	6:21	6:20	6:20	6:20	6:19	6:19	6:18	6:18	6:17	6:17	6:16	6:16	6:16	6:15	6:15	6:14	6:14	6:13	6:13
Sunset (PM)	6:23	6:22	6:22	6:22	6:22	6:21	6:21	6:21	6:20	6:20	6:20	6:19	6:19	6:19	6:19	6:18	6:18	6:18	6:17	6:17	6:17	6:16	6:16	6:16	6:16	6:15	6:15	6:15	6:15	6:14

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	12.0	6:26	6:23
2	12.0	6:25	6:22
3	12.0	6:25	6:22
4	12.0	6:24	6:22
5	12.0	6:24	6:22
6	12.0	6:23	6:21
7	12.0	6:23	6:21
8	12.0	6:23	6:21
9	12.0	6:22	6:20
10	12.0	6:22	6:20
11	12.0	6:21	6:20
12	12.0	6:21	6:19
13	12.0	6:20	6:19
14	12.0	6:20	6:19
15	12.0	6:20	6:19
16	12.0	6:19	6:18
17	12.0	6:19	6:18
18	12.0	6:18	6:18
19	12.0	6:18	6:17
20	12.0	6:17	6:17
21	12.0	6:17	6:17
22	12.0	6:16	6:16
23	12.0	6:16	6:16
24	12.0	6:16	6:16
25	12.0	6:15	6:16
26	12.0	6:15	6:15
27	12.0	6:14	6:15
28	12.0	6:14	6:15
29	12.0	6:13	6:15
30	12.0	6:13	6:14

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.16 kWh/m².

For context, solar energy here swings from a low near 3.67 kWh/m² to a high of 5.23 kWh/m² in October across the year — September's 5.16 kWh/m² sits near the top of that range.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Solar energy (kWh/m²)	5.0	5.0	5.0	5.0	5.0	5.0	5.1	5.1	5.1	5.1	5.1	5.1	5.1	5.2	5.2	5.2	5.2	5.2	5.2	5.2	5.2	5.3	5.3	5.3	5.3	5.3	5.3	5.3	5.3	5.3
Level	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright

	Solar energy (kWh/m²)	Level
1	5.0	Bright
2	5.0	Bright
3	5.0	Bright
4	5.0	Bright
5	5.0	Bright
6	5.0	Bright
7	5.1	Bright
8	5.1	Bright
9	5.1	Bright
10	5.1	Bright
11	5.1	Bright
12	5.1	Bright
13	5.1	Bright
14	5.2	Bright
15	5.2	Bright
16	5.2	Bright
17	5.2	Bright
18	5.2	Bright
19	5.2	Bright
20	5.2	Bright
21	5.2	Bright
22	5.3	Bright
23	5.3	Bright
24	5.3	Bright
25	5.3	Bright
26	5.3	Bright
27	5.3	Bright
28	5.3	Bright
29	5.3	Bright
30	5.3	Bright

Planning a trip in September

Is September a good time to visit Fonte Boa?

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

3.0

Sightseeing

4th-best month of the year

4.4

Beach & pool

3rd-best month of the year

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

What to pack for Fonte Boa in September

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

In September, Fonte Boa sees daytime highs around 31°C and nights near 24°C. Pack light clothes and rain gear. Worth having: sun protection. About 23 days see rain.

light clothesrain gearsun protection

UV index in Fonte Boa in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 11 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Fonte Boa peaks around January 21 at about 14 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 15 at about 10 (extreme).

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

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	14	14	14	14	12	11	10	11	11	12	12	12
Level	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme

	UV index (midday)	Level
Jan	14	Extreme
Feb	14	Extreme
Mar	14	Extreme
Apr	14	Extreme
May	12	Extreme
Jun	11	Extreme
Jul	10	Extreme
Aug	11	Extreme
Sep	11	Extreme
Oct	12	Extreme
Nov	12	Extreme
Dec	12	Extreme

Air quality in Fonte Boa 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 Fonte Boa is worst in March — around 17 µg/m³ PM2.5 (moderate), about 1.8× the cleanest month (June, 10 µg/m³).

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

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
PM2.5 (µg/m³)	15	16	17	15	10	10	11	17	16	14	14	14
Level	Moderate	Moderate	Moderate	Moderate	Good	Good	Good	Moderate	Moderate	Moderate	Moderate	Moderate

	PM2.5 (µg/m³)	Level
Jan	15	Moderate
Feb	16	Moderate
Mar	17	Moderate
Apr	15	Moderate
May	10	Good
Jun	10	Good
Jul	11	Good
Aug	17	Moderate
Sep	16	Moderate
Oct	14	Moderate
Nov	14	Moderate
Dec	14	Moderate

Location & terrain

Where is Fonte Boa?

Fonte Boa sits at 2.5°S, 66.1°W, 60 m above sea level, in Brazil. The nearest listed city is Maraã, 93 km away.

Topography around Fonte Boa

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

Within 3 km, the terrain around Fonte Boa has only modest variations in elevation — a maximum elevation change of 46 m around an average of 52 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 53 m; within 80 km, only modest variations in elevation — a maximum elevation change of 60 m.

The land around Fonte Boa is covered by trees (51%), grassland (22%) and water (22%) within 3 km, trees (83%) within 16 km, and trees (94%) within 80 km.

3 km

46 m

trees 51%

16 km

53 m

trees 83%

80 km

60 m

trees 94%

treesgrasslandartificial surfaceswater

← August Fonte Boa year-round climate October →Best places to visit in September

September weather nearby: Maraã 93 km · Uarini 121 km · Alvarães 163 km · Tefé 179 km · Tonantins 194 km · Santo Antônio do Içá 215 km · Carauari 278 km · São Gabriel da Cachoeira 288 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

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 Fonte Boa (-2.5139°, -66.0917°, elevation 60 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).

	Avg high (°C)	Avg low (°C)
1	31	24
2	31	24
3	31	24
4	31	24
5	31	24
6	31	24
7	31	24
8	31	24
9	31	24
10	31	24
11	31	24
12	31	24
13	31	24
14	31	24
15	31	24
16	31	24
17	31	24
18	31	24
19	31	24
20	31	24
21	31	24
22	31	24
23	31	24
24	31	24
25	31	24
26	31	24
27	31	24
28	31	24
29	31	24
30	31	24

	Clearer (%)	Cloudier (%)
1	34	66
2	33	67
3	33	67
4	33	67
5	32	68
6	32	68
7	32	68
8	31	69
9	31	69
10	31	69
11	30	70
12	30	70
13	30	70
14	31	69
15	30	70
16	30	70
17	30	70
18	30	70
19	30	70
20	29	71
21	30	70
22	30	70
23	29	71
24	29	71
25	29	71
26	28	72
27	28	72
28	27	73
29	27	73
30	26	74

	Rain chance (%)
1	78
2	78
3	78
4	78
5	78
6	78
7	77
8	77
9	77
10	77
11	77
12	77
13	77
14	77
15	77
16	78
17	78
18	78
19	78
20	78
21	78
22	78
23	78
24	78
25	77
26	77
27	77
28	77
29	77
30	77

	Oppressive (%)	Miserable (%)
1	18	82
2	18	82
3	18	82
4	18	82
5	18	82
6	17	83
7	17	83
8	17	83
9	17	83
10	17	83
11	16	84
12	16	84
13	16	84
14	15	85
15	15	85
16	14	86
17	14	86
18	13	87
19	13	87
20	13	87
21	12	88
22	12	88
23	12	88
24	12	88
25	11	89
26	11	89
27	11	89
28	11	89
29	11	89
30	11	89

	Avg high (°C)	Avg low (°C)
1	31	24
2	31	24
3	31	24
4	31	24
5	31	24
6	31	24
7	31	24
8	31	24
9	31	24
10	31	24
11	31	24
12	31	24
13	31	24
14	31	24
15	31	24
16	31	24
17	31	24
18	31	24
19	31	24
20	31	24
21	31	24
22	31	24
23	31	24
24	31	24
25	31	24
26	31	24
27	31	24
28	31	24
29	31	24
30	31	24

	Clearer (%)	Cloudier (%)
1	34	66
2	33	67
3	33	67
4	33	67
5	32	68
6	32	68
7	32	68
8	31	69
9	31	69
10	31	69
11	30	70
12	30	70
13	30	70
14	31	69
15	30	70
16	30	70
17	30	70
18	30	70
19	30	70
20	29	71
21	30	70
22	30	70
23	29	71
24	29	71
25	29	71
26	28	72
27	28	72
28	27	73
29	27	73
30	26	74

	Rain chance (%)
1	78
2	78
3	78
4	78
5	78
6	78
7	77
8	77
9	77
10	77
11	77
12	77
13	77
14	77
15	77
16	78
17	78
18	78
19	78
20	78
21	78
22	78
23	78
24	78
25	77
26	77
27	77
28	77
29	77
30	77

	Oppressive (%)	Miserable (%)
1	18	82
2	18	82
3	18	82
4	18	82
5	18	82
6	17	83
7	17	83
8	17	83
9	17	83
10	17	83
11	16	84
12	16	84
13	16	84
14	15	85
15	15	85
16	14	86
17	14	86
18	13	87
19	13	87
20	13	87
21	12	88
22	12	88
23	12	88
24	12	88
25	11	89
26	11	89
27	11	89
28	11	89
29	11	89
30	11	89

	Avg high (°C)	Avg low (°C)
1	31	24
2	31	24
3	31	24
4	31	24
5	31	24
6	31	24
7	31	24
8	31	24
9	31	24
10	31	24
11	31	24
12	31	24
13	31	24
14	31	24
15	31	24
16	31	24
17	31	24
18	31	24
19	31	24
20	31	24
21	31	24
22	31	24
23	31	24
24	31	24
25	31	24
26	31	24
27	31	24
28	31	24
29	31	24
30	31	24

	Clearer (%)	Cloudier (%)
1	34	66
2	33	67
3	33	67
4	33	67
5	32	68
6	32	68
7	32	68
8	31	69
9	31	69
10	31	69
11	30	70
12	30	70
13	30	70
14	31	69
15	30	70
16	30	70
17	30	70
18	30	70
19	30	70
20	29	71
21	30	70
22	30	70
23	29	71
24	29	71
25	29	71
26	28	72
27	28	72
28	27	73
29	27	73
30	26	74

	Rain chance (%)
1	78
2	78
3	78
4	78
5	78
6	78
7	77
8	77
9	77
10	77
11	77
12	77
13	77
14	77
15	77
16	78
17	78
18	78
19	78
20	78
21	78
22	78
23	78
24	78
25	77
26	77
27	77
28	77
29	77
30	77

	Oppressive (%)	Miserable (%)
1	18	82
2	18	82
3	18	82
4	18	82
5	18	82
6	17	83
7	17	83
8	17	83
9	17	83
10	17	83
11	16	84
12	16	84
13	16	84
14	15	85
15	15	85
16	14	86
17	14	86
18	13	87
19	13	87
20	13	87
21	12	88
22	12	88
23	12	88
24	12	88
25	11	89
26	11	89
27	11	89
28	11	89
29	11	89
30	11	89