Formosa da Serra Negra weather in December

In December, Formosa da Serra Negra sees average daytime highs of 31°C and overnight lows near 22°C, with 163 mm of rain across 21 wet days and about 12.4 hours of daylight. It is the 9th-warmest and 4th-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 8% of the time in December, and the air most often feels oppressive.

Daylight stretches from about 12 h 18 min at the start of December to 12 h 24 min by month's end. Set against the rest of the year, December is Formosa da Serra Negra's 9th-clearest and 8th-windiest month. For the whole year in context, see Formosa da Serra Negra's year-round climate.

Daytime high: 31°; 9th warmest
Overnight low: 22°; 9th coldest
Rainfall: 163 mm; 21 wet days
Daylight: 12 h 24 min; 5:50 AM – 6:12 PM
Cloud cover: 77%; 9th clearest
Wind: 6 km/h; 8th windiest
Solar energy: 4.99 kWh/m²
Travel score: 3.4; out of 10

← November Formosa da Serra Negra year-round climate January →Best places to visit in December

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

Temperature in December

Average highAverage lowShaded bands: 10–90% of days

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

A typical December day in Formosa da Serra Negra reaches about 31°C in the afternoon and slips back to 22°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, December runs about 1°C cooler than November and on par with January.

	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	31
Avg high (°C)	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	30	30	30	30	30	30	30	30	30	30	30	30	30
Avg low (°C)	23	23	23	23	23	23	23	23	22	22	22	22	22	22	22	22	22	22	22	22	22	22	22	22	22	22	22	22	22	22	22

	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	22
10	31	22
11	31	22
12	31	22
13	31	22
14	31	22
15	31	22
16	31	22
17	31	22
18	31	22
19	30	22
20	30	22
21	30	22
22	30	22
23	30	22
24	30	22
25	30	22
26	30	22
27	30	22
28	30	22
29	30	22
30	30	22
31	30	22

How December really feels in Formosa da Serra Negra

Once humidity and wind are folded in, December averages 31 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 December is heat — humidity pushes the afternoon "feels like" well above the raw temperature.

Formosa da Serra Negra weather by month

How December compares with the rest of the year at a glance. December is the 9th-warmest and 4th-wettest month here — the current month is highlighted below.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Daylight (hours)	Travel score
Jan	30° / 22°	234	26.2	12.3	3.0
Feb	30° / 22°	222	24.3	12.2	2.9
Mar	30° / 22°	236	26.8	12	2.9
Apr	31° / 22°	158	19.7	11.9	3.4
May	32° / 22°	53	9	11.7	4.3
Jun	33° / 22°	6	0.9	11.6	4.7
Jul	33° / 22°	3	0.4	11.7	4.5
Aug	34° / 22°	1	0.3	11.8	3.8
Sep	35° / 23°	12	1.7	12	3.4
Oct	33° / 23°	49	8.1	12.1	3.5
Nov	32° / 23°	112	15.5	12.3	3.6
Dec	31° / 22°	163	21	12.4	3.4

Cloud cover in December

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 8% of the time in December.

Beyond those clear spells, partly cloudy skies cover about 16% of December, with mostly cloudy or overcast conditions the remaining 76%. Skies tend to cloud over 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	31
Clearer (%)	31	31	31	31	31	31	29	29	28	28	27	25	25	24	24	23	23	22	21	21	20	20	20	20	19	19	19	19	18	17	17
Cloudier (%)	69	69	69	69	69	69	71	71	72	72	73	75	75	76	76	77	77	78	79	79	80	80	80	80	81	81	81	81	82	83	83

	Clearer (%)	Cloudier (%)
1	31	69
2	31	69
3	31	69
4	31	69
5	31	69
6	31	69
7	29	71
8	29	71
9	28	72
10	28	72
11	27	73
12	25	75
13	25	75
14	24	76
15	24	76
16	23	77
17	23	77
18	22	78
19	21	79
20	21	79
21	20	80
22	20	80
23	20	80
24	20	80
25	19	81
26	19	81
27	19	81
28	19	81
29	18	82
30	17	83
31	17	83

Chance of precipitation in December

Any precipitation

Formosa da Serra Negra gets around 163 mm of rain over 21 wet days in December. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 69% and peaks near 80% 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	31
Rain chance (%)	57	57	57	57	58	59	60	61	62	63	65	66	67	68	69	70	71	72	73	74	74	75	75	76	76	77	78	78	79	79	80

	Rain chance (%)
1	57
2	57
3	57
4	57
5	58
6	59
7	60
8	61
9	62
10	63
11	65
12	66
13	67
14	68
15	69
16	70
17	71
18	72
19	73
20	74
21	74
22	75
23	75
24	76
25	76
26	77
27	78
28	78
29	79
30	79
31	80

Humidity in December

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, December lands in the oppressive band about 94% 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	31
Muggy (%)	11	11	10	10	9	9	8	8	7	7	6	6	6	5	5	5	5	5	5	4	4	4	4	4	4	4	3	3	3	3	3
Oppressive (%)	89	89	90	90	91	91	92	92	93	93	94	94	94	95	95	95	95	95	95	96	96	96	96	96	96	96	97	97	97	97	97

	Muggy (%)	Oppressive (%)
1	11	89
2	11	89
3	10	90
4	10	90
5	9	91
6	9	91
7	8	92
8	8	92
9	7	93
10	7	93
11	6	94
12	6	94
13	6	94
14	5	95
15	5	95
16	5	95
17	5	95
18	5	95
19	5	95
20	4	96
21	4	96
22	4	96
23	4	96
24	4	96
25	4	96
26	4	96
27	3	97
28	3	97
29	3	97
30	3	97
31	3	97

Wind in December

Winds average 6 km/h in December.

Across December, daily wind ranges from about 6 km/h on the calmest days to 6 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	31
Wind speed (km/h)	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6	6
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	calm

	Wind speed (km/h)	Feels
1	6	calm
2	6	calm
3	6	calm
4	6	calm
5	6	calm
6	6	calm
7	6	calm
8	6	calm
9	6	calm
10	6	calm
11	6	calm
12	6	calm
13	6	calm
14	6	calm
15	6	calm
16	6	calm
17	6	calm
18	6	calm
19	6	calm
20	6	calm
21	6	calm
22	6	calm
23	6	calm
24	6	calm
25	6	calm
26	6	calm
27	6	calm
28	6	calm
29	6	calm
30	6	calm
31	6	calm

Sunrise & sunset in December

DaylightNight

Daylight runs from about 12 h 18 min at the start of December to 12 h 24 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 6 minutes over December. Sunrise moves from 5:44 AM to 5:57 AM, and sunset from 6:05 PM to 6:19 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	31
Daylight (h)	12.3	12.3	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4	12.4
Sunrise (AM)	5:44	5:44	5:45	5:45	5:45	5:46	5:46	5:46	5:47	5:47	5:48	5:48	5:48	5:49	5:49	5:50	5:50	5:51	5:51	5:52	5:52	5:52	5:53	5:53	5:54	5:54	5:55	5:55	5:56	5:56	5:57
Sunset (PM)	6:05	6:05	6:06	6:06	6:07	6:07	6:08	6:08	6:09	6:09	6:10	6:10	6:11	6:11	6:12	6:12	6:13	6:13	6:14	6:14	6:14	6:15	6:15	6:16	6:16	6:17	6:17	6:18	6:18	6:19	6:19

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	12.3	5:44	6:05
2	12.3	5:44	6:05
3	12.4	5:45	6:06
4	12.4	5:45	6:06
5	12.4	5:45	6:07
6	12.4	5:46	6:07
7	12.4	5:46	6:08
8	12.4	5:46	6:08
9	12.4	5:47	6:09
10	12.4	5:47	6:09
11	12.4	5:48	6:10
12	12.4	5:48	6:10
13	12.4	5:48	6:11
14	12.4	5:49	6:11
15	12.4	5:49	6:12
16	12.4	5:50	6:12
17	12.4	5:50	6:13
18	12.4	5:51	6:13
19	12.4	5:51	6:14
20	12.4	5:52	6:14
21	12.4	5:52	6:14
22	12.4	5:52	6:15
23	12.4	5:53	6:15
24	12.4	5:53	6:16
25	12.4	5:54	6:16
26	12.4	5:54	6:17
27	12.4	5:55	6:17
28	12.4	5:55	6:18
29	12.4	5:56	6:18
30	12.4	5:56	6:19
31	12.4	5:57	6:19

Solar energy in December

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in December, about 4.99 kWh/m².

For context, solar energy here swings from a low near 4.56 kWh/m² to a high of 6.44 kWh/m² in September across the year — December's 4.99 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	31
Solar energy (kWh/m²)	5.2	5.2	5.2	5.2	5.2	5.2	5.1	5.1	5.1	5.1	5.0	5.0	5.0	5.0	5.0	4.9	4.9	4.9	4.9	4.9	4.8	4.8	4.8	4.8	4.8	4.8	4.8	4.8	4.8	4.8	4.7
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	Bright

	Solar energy (kWh/m²)	Level
1	5.2	Bright
2	5.2	Bright
3	5.2	Bright
4	5.2	Bright
5	5.2	Bright
6	5.2	Bright
7	5.1	Bright
8	5.1	Bright
9	5.1	Bright
10	5.1	Bright
11	5.0	Bright
12	5.0	Bright
13	5.0	Bright
14	5.0	Bright
15	5.0	Bright
16	4.9	Bright
17	4.9	Bright
18	4.9	Bright
19	4.9	Bright
20	4.9	Bright
21	4.8	Bright
22	4.8	Bright
23	4.8	Bright
24	4.8	Bright
25	4.8	Bright
26	4.8	Bright
27	4.8	Bright
28	4.8	Bright
29	4.8	Bright
30	4.8	Bright
31	4.7	Bright

Planning a trip in December

Hazard calendar for Formosa da Serra Negra

In seasonPeak

In December, Formosa da Serra Negra sits inside its monsoon season. The full year is below, with each hazard's peak months called out.

Formosa da Serra Negra's monsoon runs November–April, when most of the year's rain falls.

Monsoon

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Is December a good time to visit Formosa da Serra Negra?

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

3.4

Sightseeing

7th-best month of the year

4.8

Beach & pool

9th-best month of the year

December is a weaker month for outdoor sightseeing in Formosa da Serra Negra.

What to pack for Formosa da Serra Negra in December

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

In December, Formosa da Serra Negra sees daytime highs around 31°C and nights near 22°C. Pack light clothes and rain gear. Worth having: sun protection. About 21 days see rain.

light clothesrain gearsun protection

UV index in Formosa da Serra Negra in December

LowModerateHighVery highExtreme

Clear-sky midday UV in December 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 Formosa da Serra Negra peaks around March 12 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 22 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	15	15	14	11	10	10	11	12	12	12	10
Level	Extreme	Extreme	Extreme	Extreme	Extreme	Very high	Extreme	Extreme	Extreme	Extreme	Extreme	Extreme

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

Air quality in Formosa da Serra Negra in December

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where December falls, not just the annual average.

Air quality in Formosa da Serra Negra is worst in October — around 24 µg/m³ PM2.5 (moderate), about 5.2× the cleanest month (June, 5 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)	12	11	11	10	7	5	5	12	20	24	19	15
Level	Good	Good	Good	Good	Good	Good	Good	Good	Moderate	Moderate	Moderate	Moderate

	PM2.5 (µg/m³)	Level
Jan	12	Good
Feb	11	Good
Mar	11	Good
Apr	10	Good
May	7	Good
Jun	5	Good
Jul	5	Good
Aug	12	Good
Sep	20	Moderate
Oct	24	Moderate
Nov	19	Moderate
Dec	15	Moderate

Location & terrain

Where is Formosa da Serra Negra?

Formosa da Serra Negra sits at 6.4°S, 46.2°W, 340 m above sea level, in Brazil. The nearest listed city is Grajaú, 70 km away.

Topography around Formosa da Serra Negra

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Formosa da Serra Negra.

Within 3 km, the terrain around Formosa da Serra Negra has only modest variations in elevation — a maximum elevation change of 110 m around an average of 294 m above sea level; within 16 km, significant variations in elevation — a maximum elevation change of 447 m; within 80 km, significant variations in elevation — a maximum elevation change of 555 m.

The land around Formosa da Serra Negra is covered by trees (45%) and grassland (45%) within 3 km, trees (50%) and grassland (34%) within 16 km, and trees (43%), grassland (33%) and shrubs (21%) within 80 km.

3 km

110 m

trees 45%

16 km

447 m

trees 50%

80 km

555 m

trees 43%

treesshrubsgrasslandcroplandartificial surfaces

← November Formosa da Serra Negra year-round climate January →Best places to visit in December

December weather nearby: Grajaú 70 km · Sítio Novo 85 km · São Raimundo das Mangabeiras 101 km · Riachão 112 km · Amarante do Maranhão 115 km · Balsas 122 km · Jenipapo dos Vieiras 134 km · Porto Franco 134 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 Formosa da Serra Negra (-6.4446°, -46.1888°, elevation 340 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	22
10	31	22
11	31	22
12	31	22
13	31	22
14	31	22
15	31	22
16	31	22
17	31	22
18	31	22
19	30	22
20	30	22
21	30	22
22	30	22
23	30	22
24	30	22
25	30	22
26	30	22
27	30	22
28	30	22
29	30	22
30	30	22
31	30	22

	Clearer (%)	Cloudier (%)
1	31	69
2	31	69
3	31	69
4	31	69
5	31	69
6	31	69
7	29	71
8	29	71
9	28	72
10	28	72
11	27	73
12	25	75
13	25	75
14	24	76
15	24	76
16	23	77
17	23	77
18	22	78
19	21	79
20	21	79
21	20	80
22	20	80
23	20	80
24	20	80
25	19	81
26	19	81
27	19	81
28	19	81
29	18	82
30	17	83
31	17	83

	Rain chance (%)
1	57
2	57
3	57
4	57
5	58
6	59
7	60
8	61
9	62
10	63
11	65
12	66
13	67
14	68
15	69
16	70
17	71
18	72
19	73
20	74
21	74
22	75
23	75
24	76
25	76
26	77
27	78
28	78
29	79
30	79
31	80

	Muggy (%)	Oppressive (%)
1	11	89
2	11	89
3	10	90
4	10	90
5	9	91
6	9	91
7	8	92
8	8	92
9	7	93
10	7	93
11	6	94
12	6	94
13	6	94
14	5	95
15	5	95
16	5	95
17	5	95
18	5	95
19	5	95
20	4	96
21	4	96
22	4	96
23	4	96
24	4	96
25	4	96
26	4	96
27	3	97
28	3	97
29	3	97
30	3	97
31	3	97

	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	22
10	31	22
11	31	22
12	31	22
13	31	22
14	31	22
15	31	22
16	31	22
17	31	22
18	31	22
19	30	22
20	30	22
21	30	22
22	30	22
23	30	22
24	30	22
25	30	22
26	30	22
27	30	22
28	30	22
29	30	22
30	30	22
31	30	22

	Clearer (%)	Cloudier (%)
1	31	69
2	31	69
3	31	69
4	31	69
5	31	69
6	31	69
7	29	71
8	29	71
9	28	72
10	28	72
11	27	73
12	25	75
13	25	75
14	24	76
15	24	76
16	23	77
17	23	77
18	22	78
19	21	79
20	21	79
21	20	80
22	20	80
23	20	80
24	20	80
25	19	81
26	19	81
27	19	81
28	19	81
29	18	82
30	17	83
31	17	83

	Rain chance (%)
1	57
2	57
3	57
4	57
5	58
6	59
7	60
8	61
9	62
10	63
11	65
12	66
13	67
14	68
15	69
16	70
17	71
18	72
19	73
20	74
21	74
22	75
23	75
24	76
25	76
26	77
27	78
28	78
29	79
30	79
31	80

	Muggy (%)	Oppressive (%)
1	11	89
2	11	89
3	10	90
4	10	90
5	9	91
6	9	91
7	8	92
8	8	92
9	7	93
10	7	93
11	6	94
12	6	94
13	6	94
14	5	95
15	5	95
16	5	95
17	5	95
18	5	95
19	5	95
20	4	96
21	4	96
22	4	96
23	4	96
24	4	96
25	4	96
26	4	96
27	3	97
28	3	97
29	3	97
30	3	97
31	3	97

	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	22
10	31	22
11	31	22
12	31	22
13	31	22
14	31	22
15	31	22
16	31	22
17	31	22
18	31	22
19	30	22
20	30	22
21	30	22
22	30	22
23	30	22
24	30	22
25	30	22
26	30	22
27	30	22
28	30	22
29	30	22
30	30	22
31	30	22

	Clearer (%)	Cloudier (%)
1	31	69
2	31	69
3	31	69
4	31	69
5	31	69
6	31	69
7	29	71
8	29	71
9	28	72
10	28	72
11	27	73
12	25	75
13	25	75
14	24	76
15	24	76
16	23	77
17	23	77
18	22	78
19	21	79
20	21	79
21	20	80
22	20	80
23	20	80
24	20	80
25	19	81
26	19	81
27	19	81
28	19	81
29	18	82
30	17	83
31	17	83

	Rain chance (%)
1	57
2	57
3	57
4	57
5	58
6	59
7	60
8	61
9	62
10	63
11	65
12	66
13	67
14	68
15	69
16	70
17	71
18	72
19	73
20	74
21	74
22	75
23	75
24	76
25	76
26	77
27	78
28	78
29	79
30	79
31	80

	Muggy (%)	Oppressive (%)
1	11	89
2	11	89
3	10	90
4	10	90
5	9	91
6	9	91
7	8	92
8	8	92
9	7	93
10	7	93
11	6	94
12	6	94
13	6	94
14	5	95
15	5	95
16	5	95
17	5	95
18	5	95
19	5	95
20	4	96
21	4	96
22	4	96
23	4	96
24	4	96
25	4	96
26	4	96
27	3	97
28	3	97
29	3	97
30	3	97
31	3	97