Iaçu weather in September

In September, Iaçu sees average daytime highs of 30°C and overnight lows near 19°C, with 11 mm of rain across 2.5 wet days and about 11.9 hours of daylight. It is the 8th-warmest and 12th-wettest month of the year here.

Highs climb over the month, from about 30°C in the first days to 31°C by the end. The sky is clear or mostly clear about 28% of the time in September, and the air most often feels humid.

Daylight stretches from about 11 h 48 min at the start of September to 12 h 06 min by month's end. Set against the rest of the year, September is Iaçu's 2nd-clearest and 2nd-windiest month. For the whole year in context, see Iaçu's year-round climate.

Daytime high: 30°; 8th warmest
Overnight low: 19°; 4th coldest
Rainfall: 11 mm; 2.5 wet days
Daylight: 11 h 54 min; 5:37 AM – 5:33 PM
Cloud cover: 55%; 2nd clearest
Wind: 11 km/h; 2nd windiest
Solar energy: 5.03 kWh/m²
Travel score: 5.6; out of 10

Iaçu is human settlement in Brazil.

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

← August Iaçu 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

Highs climb over the month, from about 30°C in the first days to 31°C by the end.

A typical September day in Iaçu reaches about 30°C in the afternoon and slips back to 19°C overnight — a 11°C spread between the day's warmth and the night's chill. On most days the high lands between 28°C and 33°C. Set against its neighbours, September runs about 2°C warmer than August and about 1°C cooler than 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)	30	30	30	30	30	30	30	30	30	30	30	30	30	30	30	30	31	31	31	31	31	31	31	31	31	31	31	31	31	31
Avg low (°C)	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	19	20	20	20	20	20	20	20	20	20	20	20	20	20	20

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

How September really feels in Iaçu

Once humidity and wind are folded in, September averages 1 day 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

heat index over the day's high

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.

Iaçu weather by month

How September compares with the rest of the year at a glance. September is the 8th-warmest and 12th-wettest month here — the current month is highlighted below.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Daylight (hours)	Travel score
Jan	32° / 22°	56	6.6	12.7	4.0
Feb	33° / 22°	37	6.1	12.4	3.8
Mar	33° / 22°	53	8.1	12.1	3.9
Apr	31° / 22°	37	7.1	11.7	4.5
May	30° / 21°	18	5.1	11.4	5.4
Jun	29° / 19°	14	4.6	11.3	6.2
Jul	28° / 18°	14	4.8	11.3	6.6
Aug	29° / 18°	11	3.7	11.6	6.3
Sep	30° / 19°	11	2.5	11.9	5.6
Oct	32° / 21°	21	4	12.3	4.7
Nov	32° / 22°	53	7.1	12.6	4.3
Dec	32° / 22°	55	6.6	12.7	4.2

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 28% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 28% of September, with mostly cloudy or overcast conditions the remaining 44%. Skies tend to open up as the month goes on.

	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 (%)	53	53	54	54	54	54	54	55	55	56	56	56	56	56	57	57	57	57	57	56	57	57	57	57	57	57	57	57	58	58
Cloudier (%)	47	47	46	46	46	46	46	45	45	44	44	44	44	44	43	43	43	43	43	44	43	43	43	43	43	43	43	43	42	42

	Clearer (%)	Cloudier (%)
1	53	47
2	53	47
3	54	46
4	54	46
5	54	46
6	54	46
7	54	46
8	55	45
9	55	45
10	56	44
11	56	44
12	56	44
13	56	44
14	56	44
15	57	43
16	57	43
17	57	43
18	57	43
19	57	43
20	56	44
21	57	43
22	57	43
23	57	43
24	57	43
25	57	43
26	57	43
27	57	43
28	57	43
29	58	42
30	58	42

Chance of precipitation in September

Any precipitation

Iaçu gets around 11 mm of rain over 2.5 wet days in September, the driest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 9% and peaks near 11% 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 (%)	9	9	9	9	9	9	9	8	8	8	8	8	9	9	9	9	9	9	9	9	9	9	9	9	10	10	10	10	11	11

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

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 68% of days. Sticky, muggy-or-worse air turns up on roughly 22% 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
Dry (%)	1	1	1	1	1	1	1	1	1	1	1	1	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0
Comfortable (%)	15	15	15	15	15	15	15	14	14	13	13	12	11	10	10	9	8	8	7	7	7	6	6	6	5	5	5	5	5	4
Humid (%)	70	70	70	69	69	69	69	70	70	70	70	70	71	72	71	71	71	70	70	69	68	67	66	64	64	63	62	61	60	60
Muggy (%)	14	14	14	15	15	15	15	15	15	16	16	17	18	18	19	20	21	22	23	24	25	27	28	30	31	32	33	34	35	36

	Dry (%)	Comfortable (%)	Humid (%)	Muggy (%)
1	1	15	70	14
2	1	15	70	14
3	1	15	70	14
4	1	15	69	15
5	1	15	69	15
6	1	15	69	15
7	1	15	69	15
8	1	14	70	15
9	1	14	70	15
10	1	13	70	16
11	1	13	70	16
12	1	12	70	17
13	0	11	71	18
14	0	10	72	18
15	0	10	71	19
16	0	9	71	20
17	0	8	71	21
18	0	8	70	22
19	0	7	70	23
20	0	7	69	24
21	0	7	68	25
22	0	6	67	27
23	0	6	66	28
24	0	6	64	30
25	0	5	64	31
26	0	5	63	32
27	0	5	62	33
28	0	5	61	34
29	0	5	60	35
30	0	4	60	36

Wind in September

Winds average 11 km/h in September.

Across September, daily wind ranges from about 10 km/h on the calmest days to 11 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)	10	10	10	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11
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	10	calm
2	10	calm
3	10	calm
4	11	calm
5	11	calm
6	11	calm
7	11	calm
8	11	calm
9	11	calm
10	11	calm
11	11	calm
12	11	calm
13	11	calm
14	11	calm
15	11	calm
16	11	calm
17	11	calm
18	11	calm
19	11	calm
20	11	calm
21	11	calm
22	11	calm
23	11	calm
24	11	calm
25	11	calm
26	11	calm
27	11	calm
28	11	calm
29	11	calm
30	11	calm

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 h 48 min at the start of September to 12 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 18 minutes over September. Sunrise moves from 5:48 AM to 5:27 AM, and sunset from 5:33 PM to 5:33 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)	11.8	11.8	11.8	11.8	11.8	11.8	11.8	11.8	11.8	11.9	11.9	11.9	11.9	11.9	11.9	11.9	11.9	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.1	12.1	12.1	12.1	12.1
Sunrise (AM)	5:48	5:47	5:47	5:46	5:45	5:45	5:44	5:43	5:42	5:42	5:41	5:40	5:39	5:39	5:38	5:37	5:37	5:36	5:35	5:34	5:34	5:33	5:32	5:31	5:31	5:30	5:29	5:29	5:28	5:27
Sunset (PM)	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33	5:33

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	11.8	5:48	5:33
2	11.8	5:47	5:33
3	11.8	5:47	5:33
4	11.8	5:46	5:33
5	11.8	5:45	5:33
6	11.8	5:45	5:33
7	11.8	5:44	5:33
8	11.8	5:43	5:33
9	11.8	5:42	5:33
10	11.9	5:42	5:33
11	11.9	5:41	5:33
12	11.9	5:40	5:33
13	11.9	5:39	5:33
14	11.9	5:39	5:33
15	11.9	5:38	5:33
16	11.9	5:37	5:33
17	11.9	5:37	5:33
18	12.0	5:36	5:33
19	12.0	5:35	5:33
20	12.0	5:34	5:33
21	12.0	5:34	5:33
22	12.0	5:33	5:33
23	12.0	5:32	5:33
24	12.0	5:31	5:33
25	12.0	5:31	5:33
26	12.1	5:30	5:33
27	12.1	5:29	5:33
28	12.1	5:29	5:33
29	12.1	5:28	5:33
30	12.1	5:27	5:33

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.03 kWh/m².

For context, solar energy here swings from a low near 3.52 kWh/m² to a high of 6.01 kWh/m² in January across the year — September's 5.03 kWh/m² falls in the middle.

	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)	4.6	4.6	4.7	4.7	4.7	4.8	4.8	4.8	4.8	4.9	4.9	4.9	5.0	5.0	5.0	5.0	5.1	5.1	5.1	5.2	5.2	5.2	5.3	5.3	5.3	5.3	5.4	5.4	5.4	5.4
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	4.6	Bright
2	4.6	Bright
3	4.7	Bright
4	4.7	Bright
5	4.7	Bright
6	4.8	Bright
7	4.8	Bright
8	4.8	Bright
9	4.8	Bright
10	4.9	Bright
11	4.9	Bright
12	4.9	Bright
13	5.0	Bright
14	5.0	Bright
15	5.0	Bright
16	5.0	Bright
17	5.1	Bright
18	5.1	Bright
19	5.1	Bright
20	5.2	Bright
21	5.2	Bright
22	5.2	Bright
23	5.3	Bright
24	5.3	Bright
25	5.3	Bright
26	5.3	Bright
27	5.4	Bright
28	5.4	Bright
29	5.4	Bright
30	5.4	Bright

Planning a trip in September

Is September a good time to visit Iaçu?

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

5.6

Sightseeing

4th-best month of the year

7.9

Beach & pool

1st-best month of the year

September is a reasonable time to visit Iaçu for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for Iaçu in September

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

In September, Iaçu sees daytime highs around 30°C and nights near 19°C. Pack light clothes. Worth having: sun protection.

light clothessun protection

UV index in Iaçu 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 Iaçu peaks around February 17 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near July 10 at about 9 (very high).

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	15	14	12	9	9	9	10	11	13	13	12
Level	Extreme	Extreme	Extreme	Extreme	Very high	Very high	Very high	Extreme	Extreme	Extreme	Extreme	Extreme

	UV index (midday)	Level
Jan	14	Extreme
Feb	15	Extreme
Mar	14	Extreme
Apr	12	Extreme
May	9	Very high
Jun	9	Very high
Jul	9	Very high
Aug	10	Extreme
Sep	11	Extreme
Oct	13	Extreme
Nov	13	Extreme
Dec	12	Extreme

Location & terrain

Where is Iaçu?

Iaçu sits at 12.8°S, 40.2°W, 240 m above sea level, in Brazil. The nearest listed city is Itaberaba, 29 km away.

Topography around Iaçu

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

Within 3 km, the terrain around Iaçu has only modest variations in elevation — a maximum elevation change of 228 m around an average of 251 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 598 m; within 80 km, large variations in elevation — a maximum elevation change of 928 m.

The land around Iaçu is covered by grassland (61%) within 3 km, grassland (67%) within 16 km, and grassland (58%) and trees (27%) within 80 km.

3 km

228 m

grassland 61%

16 km

598 m

grassland 67%

80 km

928 m

grassland 58%

treesshrubsgrasslandcroplandartificial surfaceswater

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

September weather nearby: Itaberaba 29 km · Boa Vista do Tupim 44 km · Itatim 56 km · Ruy Barbosa 62 km · Amargosa 72 km · Maracás 79 km · Ubaíra 81 km · Castro Alves 85 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 Iaçu (-12.7672°, -40.2117°, elevation 240 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. 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	30	19
2	30	19
3	30	19
4	30	19
5	30	19
6	30	19
7	30	19
8	30	19
9	30	19
10	30	19
11	30	19
12	30	19
13	30	19
14	30	19
15	30	19
16	30	19
17	31	20
18	31	20
19	31	20
20	31	20
21	31	20
22	31	20
23	31	20
24	31	20
25	31	20
26	31	20
27	31	20
28	31	20
29	31	20
30	31	20

	Clearer (%)	Cloudier (%)
1	53	47
2	53	47
3	54	46
4	54	46
5	54	46
6	54	46
7	54	46
8	55	45
9	55	45
10	56	44
11	56	44
12	56	44
13	56	44
14	56	44
15	57	43
16	57	43
17	57	43
18	57	43
19	57	43
20	56	44
21	57	43
22	57	43
23	57	43
24	57	43
25	57	43
26	57	43
27	57	43
28	57	43
29	58	42
30	58	42

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

	Dry (%)	Comfortable (%)	Humid (%)	Muggy (%)
1	1	15	70	14
2	1	15	70	14
3	1	15	70	14
4	1	15	69	15
5	1	15	69	15
6	1	15	69	15
7	1	15	69	15
8	1	14	70	15
9	1	14	70	15
10	1	13	70	16
11	1	13	70	16
12	1	12	70	17
13	0	11	71	18
14	0	10	72	18
15	0	10	71	19
16	0	9	71	20
17	0	8	71	21
18	0	8	70	22
19	0	7	70	23
20	0	7	69	24
21	0	7	68	25
22	0	6	67	27
23	0	6	66	28
24	0	6	64	30
25	0	5	64	31
26	0	5	63	32
27	0	5	62	33
28	0	5	61	34
29	0	5	60	35
30	0	4	60	36

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

	Clearer (%)	Cloudier (%)
1	53	47
2	53	47
3	54	46
4	54	46
5	54	46
6	54	46
7	54	46
8	55	45
9	55	45
10	56	44
11	56	44
12	56	44
13	56	44
14	56	44
15	57	43
16	57	43
17	57	43
18	57	43
19	57	43
20	56	44
21	57	43
22	57	43
23	57	43
24	57	43
25	57	43
26	57	43
27	57	43
28	57	43
29	58	42
30	58	42

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

	Dry (%)	Comfortable (%)	Humid (%)	Muggy (%)
1	1	15	70	14
2	1	15	70	14
3	1	15	70	14
4	1	15	69	15
5	1	15	69	15
6	1	15	69	15
7	1	15	69	15
8	1	14	70	15
9	1	14	70	15
10	1	13	70	16
11	1	13	70	16
12	1	12	70	17
13	0	11	71	18
14	0	10	72	18
15	0	10	71	19
16	0	9	71	20
17	0	8	71	21
18	0	8	70	22
19	0	7	70	23
20	0	7	69	24
21	0	7	68	25
22	0	6	67	27
23	0	6	66	28
24	0	6	64	30
25	0	5	64	31
26	0	5	63	32
27	0	5	62	33
28	0	5	61	34
29	0	5	60	35
30	0	4	60	36

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

	Clearer (%)	Cloudier (%)
1	53	47
2	53	47
3	54	46
4	54	46
5	54	46
6	54	46
7	54	46
8	55	45
9	55	45
10	56	44
11	56	44
12	56	44
13	56	44
14	56	44
15	57	43
16	57	43
17	57	43
18	57	43
19	57	43
20	56	44
21	57	43
22	57	43
23	57	43
24	57	43
25	57	43
26	57	43
27	57	43
28	57	43
29	58	42
30	58	42

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

	Dry (%)	Comfortable (%)	Humid (%)	Muggy (%)
1	1	15	70	14
2	1	15	70	14
3	1	15	70	14
4	1	15	69	15
5	1	15	69	15
6	1	15	69	15
7	1	15	69	15
8	1	14	70	15
9	1	14	70	15
10	1	13	70	16
11	1	13	70	16
12	1	12	70	17
13	0	11	71	18
14	0	10	72	18
15	0	10	71	19
16	0	9	71	20
17	0	8	71	21
18	0	8	70	22
19	0	7	70	23
20	0	7	69	24
21	0	7	68	25
22	0	6	67	27
23	0	6	66	28
24	0	6	64	30
25	0	5	64	31
26	0	5	63	32
27	0	5	62	33
28	0	5	61	34
29	0	5	60	35
30	0	4	60	36