Atalaia do Norte weather in September

In September, Atalaia do Norte sees average daytime highs of 31°C and overnight lows near 23°C, with 163 mm of rain across 24.1 wet days and about 12 hours of daylight. It is the 1st-warmest and 10th-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 11% of the time in September, and the air most often feels miserable.

Daylight stretches from about 11 h 54 min at the start of September to 12 hours by month's end. Set against the rest of the year, September is Atalaia do Norte's 3rd-clearest and 7th-windiest month. For the whole year in context, see Atalaia do Norte's year-round climate.

Daytime high: 31°; 1st warmest
Overnight low: 23°; 4th coldest
Rainfall: 163 mm; 24.1 wet days
Daylight: 12 hours; 5:36 AM – 5:34 PM
Cloud cover: 71%; 3rd clearest
Wind: 4 km/h; 7th windiest
Solar energy: 5.1 kWh/m²
Travel score: 3.0; out of 10

← August Atalaia do Norte 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 Atalaia do Norte reaches about 31°C in the afternoon and slips back to 23°C overnight — a 8°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 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)	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23	23

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

How September really feels in Atalaia do Norte

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

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.

Atalaia do Norte weather by month

How September compares with the rest of the year at a glance. September is the 1st-warmest and 10th-wettest month here — the current month is highlighted below.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Daylight (hours)	Travel score
Jan	30° / 24°	312	28.8	12.2	2.7
Feb	30° / 24°	301	26.3	12.1	2.7
Mar	30° / 24°	344	29.3	12	2.7
Apr	30° / 23°	291	27.7	11.9	2.8
May	29° / 23°	256	27.2	11.8	3.1
Jun	29° / 23°	185	24.6	11.8	3.4
Jul	29° / 22°	146	23.1	11.8	3.7
Aug	30° / 23°	135	22.4	11.9	3.5
Sep	31° / 23°	163	24.1	12	3.0
Oct	31° / 23°	210	26.5	12.1	2.8
Nov	31° / 24°	230	27	12.2	2.6
Dec	30° / 24°	292	29.2	12.2	2.7

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 11% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 21% of September, with mostly cloudy or overcast conditions the remaining 68%.

	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 (%)	37	38	38	38	37	37	37	37	36	36	36	35	34	33	33	32	31	30	30	30	28	28	28	27	26	25	25	25	24	24
Cloudier (%)	63	62	62	62	63	63	63	63	64	64	64	65	66	67	67	68	69	70	70	70	72	72	72	73	74	75	75	75	76	76

	Clearer (%)	Cloudier (%)
1	37	63
2	38	62
3	38	62
4	38	62
5	37	63
6	37	63
7	37	63
8	37	63
9	36	64
10	36	64
11	36	64
12	35	65
13	34	66
14	33	67
15	33	67
16	32	68
17	31	69
18	30	70
19	30	70
20	30	70
21	28	72
22	28	72
23	28	72
24	27	73
25	26	74
26	25	75
27	25	75
28	25	75
29	24	76
30	24	76

Chance of precipitation in September

Any precipitation

Atalaia do Norte gets around 163 mm of rain over 24.1 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 80% and peaks near 85% on the wettest days. The odds climb toward the end of the month.

	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 (%)	76	76	76	77	77	77	78	78	78	78	79	79	79	80	80	80	80	81	81	81	82	82	82	83	83	84	84	84	85	85

	Rain chance (%)
1	76
2	76
3	76
4	77
5	77
6	77
7	78
8	78
9	78
10	78
11	79
12	79
13	79
14	80
15	80
16	80
17	80
18	81
19	81
20	81
21	82
22	82
23	82
24	83
25	83
26	84
27	84
28	84
29	85
30	85

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 54% 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
Muggy (%)	3	3	3	2	2	2	2	2	2	2	2	2	2	2	2	1	1	1	1	1	1	1	1	1	0	0	0	0	0	0
Oppressive (%)	51	51	50	51	50	50	49	49	49	48	48	47	46	45	45	44	43	43	42	42	41	40	40	39	39	38	38	38	37	37
Miserable (%)	46	46	47	47	48	48	48	49	49	50	50	51	52	53	53	55	56	56	57	57	58	59	59	60	61	62	62	62	63	63

	Muggy (%)	Oppressive (%)	Miserable (%)
1	3	51	46
2	3	51	46
3	3	50	47
4	2	51	47
5	2	50	48
6	2	50	48
7	2	49	48
8	2	49	49
9	2	49	49
10	2	48	50
11	2	48	50
12	2	47	51
13	2	46	52
14	2	45	53
15	2	45	53
16	1	44	55
17	1	43	56
18	1	43	56
19	1	42	57
20	1	42	57
21	1	41	58
22	1	40	59
23	1	40	59
24	1	39	60
25	0	39	61
26	0	38	62
27	0	38	62
28	0	38	62
29	0	37	63
30	0	37	63

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 11 h 54 min 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 6 minutes over September. Sunrise moves from 5:43 AM to 5:29 AM, and sunset from 5:38 PM to 5:31 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)	11.9	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	12.0	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)	5:43	5:43	5:42	5:42	5:41	5:41	5:40	5:40	5:39	5:39	5:38	5:38	5:37	5:37	5:36	5:36	5:35	5:35	5:34	5:34	5:33	5:33	5:32	5:32	5:31	5:31	5:30	5:30	5:30	5:29
Sunset (PM)	5:38	5:38	5:38	5:37	5:37	5:37	5:37	5:36	5:36	5:36	5:36	5:35	5:35	5:35	5:35	5:34	5:34	5:34	5:34	5:33	5:33	5:33	5:33	5:32	5:32	5:32	5:32	5:32	5:31	5:31

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

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.1 kWh/m² — the sunniest month for solar.

For context, solar energy here swings from a low near 3.8 kWh/m² to a high of 5.1 kWh/m² in September across the year — September's 5.1 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	5.0	5.0	5.0	5.1	5.1	5.1	5.1	5.1	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	5.2
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	5.0	Bright
8	5.0	Bright
9	5.0	Bright
10	5.1	Bright
11	5.1	Bright
12	5.1	Bright
13	5.1	Bright
14	5.1	Bright
15	5.1	Bright
16	5.1	Bright
17	5.1	Bright
18	5.1	Bright
19	5.1	Bright
20	5.1	Bright
21	5.1	Bright
22	5.2	Bright
23	5.2	Bright
24	5.2	Bright
25	5.2	Bright
26	5.2	Bright
27	5.2	Bright
28	5.2	Bright
29	5.2	Bright
30	5.2	Bright

Planning a trip in September

Is September a good time to visit Atalaia do Norte?

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

3.0

Sightseeing

5th-best month of the year

4.4

Beach & pool

4th-best month of the year

September is a weaker month for outdoor sightseeing in Atalaia do Norte.

What to pack for Atalaia do Norte in September

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

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

light clothesrain gearsun protection

UV index in Atalaia do Norte in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 10 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Atalaia do Norte peaks around February 18 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near August 16 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)	15	16	15	13	12	10	10	9	10	12	13	12
Level	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme	Very high	Very high	Very high	Extreme	Extreme	Extreme

	UV index (midday)	Level
Jan	15	Extreme
Feb	16	Extreme
Mar	15	Extreme
Apr	13	Extreme
May	12	Extreme
Jun	10	Extreme
Jul	10	Very high
Aug	9	Very high
Sep	10	Very high
Oct	12	Extreme
Nov	13	Extreme
Dec	12	Extreme

Air quality in Atalaia do Norte 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 Atalaia do Norte is worst in September — around 17 µg/m³ PM2.5 (moderate), about 2.0× the cleanest month (June, 8 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)	13	14	13	11	9	8	10	16	17	11	11	11
Level	Moderate	Moderate	Moderate	Good	Good	Good	Good	Moderate	Moderate	Good	Good	Good

	PM2.5 (µg/m³)	Level
Jan	13	Moderate
Feb	14	Moderate
Mar	13	Moderate
Apr	11	Good
May	9	Good
Jun	8	Good
Jul	10	Good
Aug	16	Moderate
Sep	17	Moderate
Oct	11	Good
Nov	11	Good
Dec	11	Good

Location & terrain

Where is Atalaia do Norte?

Atalaia do Norte sits at 4.4°S, 70.2°W, 84 m above sea level, in Brazil. The nearest listed city is Benjamin Constant, 18 km away.

Topography around Atalaia do Norte

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

Within 3 km, the terrain around Atalaia do Norte has only modest variations in elevation — a maximum elevation change of 49 m around an average of 81 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 71 m; within 80 km, only modest variations in elevation — a maximum elevation change of 130 m.

The land around Atalaia do Norte is covered by trees (82%) within 3 km, trees (92%) within 16 km, and trees (96%) within 80 km.

3 km

49 m

trees 82%

16 km

71 m

trees 92%

80 km

130 m

trees 96%

treesgrasslandartificial surfaceswater

← August Atalaia do Norte year-round climate October →Best places to visit in September

September weather nearby: Benjamin Constant 18 km · Tabatinga 32 km · Leticia 33 km · São Paulo de Olivença 183 km · Eirunepé 257 km · Santo Antônio do Içá 287 km · Tonantins 313 km · Ipixuna 342 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 Atalaia do Norte (-4.3665°, -70.1919°, elevation 84 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	23
2	31	23
3	31	23
4	31	23
5	31	23
6	31	23
7	31	23
8	31	23
9	31	23
10	31	23
11	31	23
12	31	23
13	31	23
14	31	23
15	31	23
16	31	23
17	31	23
18	31	23
19	31	23
20	31	23
21	31	23
22	31	23
23	31	23
24	31	23
25	31	23
26	31	23
27	31	23
28	31	23
29	31	23
30	31	23

	Clearer (%)	Cloudier (%)
1	37	63
2	38	62
3	38	62
4	38	62
5	37	63
6	37	63
7	37	63
8	37	63
9	36	64
10	36	64
11	36	64
12	35	65
13	34	66
14	33	67
15	33	67
16	32	68
17	31	69
18	30	70
19	30	70
20	30	70
21	28	72
22	28	72
23	28	72
24	27	73
25	26	74
26	25	75
27	25	75
28	25	75
29	24	76
30	24	76

	Rain chance (%)
1	76
2	76
3	76
4	77
5	77
6	77
7	78
8	78
9	78
10	78
11	79
12	79
13	79
14	80
15	80
16	80
17	80
18	81
19	81
20	81
21	82
22	82
23	82
24	83
25	83
26	84
27	84
28	84
29	85
30	85

	Muggy (%)	Oppressive (%)	Miserable (%)
1	3	51	46
2	3	51	46
3	3	50	47
4	2	51	47
5	2	50	48
6	2	50	48
7	2	49	48
8	2	49	49
9	2	49	49
10	2	48	50
11	2	48	50
12	2	47	51
13	2	46	52
14	2	45	53
15	2	45	53
16	1	44	55
17	1	43	56
18	1	43	56
19	1	42	57
20	1	42	57
21	1	41	58
22	1	40	59
23	1	40	59
24	1	39	60
25	0	39	61
26	0	38	62
27	0	38	62
28	0	38	62
29	0	37	63
30	0	37	63

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

	Clearer (%)	Cloudier (%)
1	37	63
2	38	62
3	38	62
4	38	62
5	37	63
6	37	63
7	37	63
8	37	63
9	36	64
10	36	64
11	36	64
12	35	65
13	34	66
14	33	67
15	33	67
16	32	68
17	31	69
18	30	70
19	30	70
20	30	70
21	28	72
22	28	72
23	28	72
24	27	73
25	26	74
26	25	75
27	25	75
28	25	75
29	24	76
30	24	76

	Rain chance (%)
1	76
2	76
3	76
4	77
5	77
6	77
7	78
8	78
9	78
10	78
11	79
12	79
13	79
14	80
15	80
16	80
17	80
18	81
19	81
20	81
21	82
22	82
23	82
24	83
25	83
26	84
27	84
28	84
29	85
30	85

	Muggy (%)	Oppressive (%)	Miserable (%)
1	3	51	46
2	3	51	46
3	3	50	47
4	2	51	47
5	2	50	48
6	2	50	48
7	2	49	48
8	2	49	49
9	2	49	49
10	2	48	50
11	2	48	50
12	2	47	51
13	2	46	52
14	2	45	53
15	2	45	53
16	1	44	55
17	1	43	56
18	1	43	56
19	1	42	57
20	1	42	57
21	1	41	58
22	1	40	59
23	1	40	59
24	1	39	60
25	0	39	61
26	0	38	62
27	0	38	62
28	0	38	62
29	0	37	63
30	0	37	63

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

	Clearer (%)	Cloudier (%)
1	37	63
2	38	62
3	38	62
4	38	62
5	37	63
6	37	63
7	37	63
8	37	63
9	36	64
10	36	64
11	36	64
12	35	65
13	34	66
14	33	67
15	33	67
16	32	68
17	31	69
18	30	70
19	30	70
20	30	70
21	28	72
22	28	72
23	28	72
24	27	73
25	26	74
26	25	75
27	25	75
28	25	75
29	24	76
30	24	76

	Rain chance (%)
1	76
2	76
3	76
4	77
5	77
6	77
7	78
8	78
9	78
10	78
11	79
12	79
13	79
14	80
15	80
16	80
17	80
18	81
19	81
20	81
21	82
22	82
23	82
24	83
25	83
26	84
27	84
28	84
29	85
30	85

	Muggy (%)	Oppressive (%)	Miserable (%)
1	3	51	46
2	3	51	46
3	3	50	47
4	2	51	47
5	2	50	48
6	2	50	48
7	2	49	48
8	2	49	49
9	2	49	49
10	2	48	50
11	2	48	50
12	2	47	51
13	2	46	52
14	2	45	53
15	2	45	53
16	1	44	55
17	1	43	56
18	1	43	56
19	1	42	57
20	1	42	57
21	1	41	58
22	1	40	59
23	1	40	59
24	1	39	60
25	0	39	61
26	0	38	62
27	0	38	62
28	0	38	62
29	0	37	63
30	0	37	63