Last updated: August 21, 2025
December in Oeiras, Brazil is characterized by a warm and humid climate, where temperatures can soar to a maximum of 39°C (102°F), with an average of 29°C (84°F) and a minimum of 22°C (72°F). While the weather is predominantly sunny, rainfall is not uncommon, bringing about 81 mm (3.2 in) of precipitation over approximately 10 days of the month. This combination of warmth and moisture creates a lively atmosphere, perfect for enjoying the vibrant local culture amidst the lush, tropical scenery.
In Oeiras, Brazil, December brings a delightful end to the year, with temperatures offering a warm embrace. The month typically sees minimums around 22°C (72°F) and averages of 29°C (84°F), perfect for outdoor activities and festivities. With maximum temperatures peaking at 39°C (102°F), the heat continues a trend established throughout the previous months, where temperatures steadily climbed from the milder averages of earlier in the year. As autumn transitions into summer, December serves as a warm invitation to explore the region's vibrant culture and natural beauty under the Brazilian sun.
In December, Oeiras, Brazil experiences a notable uptick in precipitation, with 81 mm (3.2 in) of rain over 10 days, marking a transitional phase as the region shifts from the drier half of the year to a more humid climate. Following a sparse rainfall pattern during the dry months of June to August, where not a single drop fell, December's precipitation is a significant relief for the environment. This spike in rainfall follows November's 51 mm (2.0 in), suggesting a consistent increase towards the end of the year. While December’s rainfall is slightly lower than January's 82 mm (3.2 in), the trend indicates the onset of the rainy season, setting the stage for the wetter months ahead. Thus, December serves as a crucial precursor to the lush tropical climate that characterizes Oeiras in the months following.
In December, Oeiras, Brazil, experiences a notable shift in humidity levels as they rise to 67%, a marked increase from the significantly lower 41% recorded in November. This uptick signals the transition into the wetter summer months, following a steady downward trend from the peak of 93% in March. The humidity consistently decreases from mid-year, reaching its lowest in October at 45% before beginning its climb again. As the year wraps up, December's humidity brings a refreshing atmospheric change, hinting at the lush, vibrant characteristics that summer holds for this Brazilian town.
In Oeiras, Brazil, the December UV Index remains strikingly high, peaking at an index of 14, which falls into the extreme exposure category. This trend of persistent extreme UV levels continues throughout the year, with January through April also reporting indices of 14 or higher. The intensity subsides slightly in the mid-year months, with readings ranging from 11 to 12, before rising again in late fall. Despite brief fluctuations, the consistent need for caution against sunburn is evident, with a mere 10 minutes of exposure being enough to risk skin damage. For those planning outdoor activities, it's crucial to stay informed about the UV Index. For more insights, visit Oeiras UV Index.
UV Risk Categories
December in Oeiras, Brazil, shines with 327 hours of sunlight, making it a delightful close to the year. As the month glides into summer, sunlight begins to peak, showcasing a promising trend that starts in the earlier months. January kicks off with 251 hours, gradually increasing as the seasons roll on, with February and March revealing 265 and 303 hours respectively. By August, the sun reaches its zenith with a dazzling 348 hours, and even as the year winds down, December maintains a robust brightness, mirroring November's golden glow. This consistent abundance of sunshine not only illuminates Oeiras but also enhances its reputation as a radiant haven throughout the year.
In Oeiras, Brazil, December marks a notable dip in sunny weather, with a 17% chance of sunshine. This decline follows a gradual rise in sunshine probability from the cooler months, peaking in July and August at 77% and 81% respectively. As the year progresses into the initial months of the rainy season, which spans from December to February, the likelihood of clear, sunny skies lessens significantly. This trend suggests that while holiday festivities may be in full swing, residents and visitors should prepare for a mix of overcast days and occasional rain, contrasting sharply with the more consistently bright and warm months that precede it.
In Oeiras, Brazil, the daylight duration exhibits an intriguing pattern throughout the year. From January to March, residents bask in a consistent 12 hours of daylight, creating a bright and lively atmosphere ideal for outdoor activities. As April ushers in the cooler months, daylight dips slightly to 11 hours, a change that remains steady through the winter months of May to August. Interestingly, as spring rolls back in September, daylight returns to the comforting 12 hours, continuing steadily until December. This rhythmic cycle highlights the harmonious balance of light and dark that characterizes life in Oeiras, allowing both residents and visitors to enjoy the vibrant energy throughout the year.
In Oeiras, Brazil, December sees a gentle breeze, with average wind speeds hovering around 1.8 m/s (4 mph). This marks a subtle increase from the calmer winds of November, which experienced an average of 1.7 m/s (4 mph). Throughout the year, wind speeds gradually ramp up, peaking in August with 4.6 m/s (10 mph), before tapering off in the latter months. December's breezy conditions create a pleasant atmosphere as the air warms, allowing residents and visitors alike to enjoy the outdoors. The trend of gradually escalating winds throughout the colder months sets the stage for a refreshing end to the year, making December's mild winds a welcome transition from the heavier gusts of summer.
Weather in Oeiras varies notably across the year, with each month offering distinct climate conditions. This page compares December’s weather to other months in Oeiras, focusing on differences in temperature, rainfall, humidity, and UV levels.
In December, the weather typically showcases a warm range of temperatures, with a minimum of 22°C (72°F) and an average temperature of 29°C (84°F), peaking at a maximum of 39°C (102°F). The month sees approximately 81 mm (3.2 in) of precipitation spread over about 10 days, accompanied by a humidity level of 67%.
In contrast, January experiences slightly cooler average temperatures, with minimums still around 22°C (71°F) and an average of 28°C (82°F). However, it also witnesses a similar maximum of 39°C (103°F) and a marginally increased rainfall of 82 mm (3.2 in) over 14 days, resulting in a much higher humidity level of 90%. For more details, check out Oeiras weather in January.
In December, the weather is typically warm, with temperatures ranging from a minimum of 22°C (72°F) to a maximum of 39°C (102°F) and an average of 29°C (84°F). This month sees around 81 mm (3.2 in) of precipitation over approximately 10 days, accompanied by a humidity level of 67%. In contrast, February experiences slightly cooler temperatures, with averages dropping to 27°C (81°F) and a maximum of 37°C (98°F), while maintaining a consistent minimum of 22°C (72°F). However, February is much wetter, receiving a significant 217 mm (8.5 in) of rainfall over 21 days, and the humidity rises to 91%. For more insight into the climate during this month, you can refer to Oeiras weather in February.
In December, the weather typically showcases warmer temperatures, with a minimum of 22°C (72°F) and an average high reaching up to 39°C (102°F), accompanied by relatively moderate humidity at 67%. However, this month experiences about 81 mm (3.2 in) of precipitation spread over 10 days. In contrast, March brings cooler temperatures, with a minimum of 21°C (70°F) and an average maximum of 35°C (94°F). This month also sees significantly higher rainfall, totaling 159 mm (6.3 in) across 22 days and much higher humidity at 93%. For more detailed insights into March weather patterns, you can visit Oeiras weather in March.
In December, the weather is characterized by high temperatures, with a minimum of 22°C (72°F) and an average of 29°C (84°F), reaching a maximum of 39°C (102°F). Despite the warmth, there is some rainfall, averaging 81 mm (3.2 in) over about 10 days, along with a relatively moderate humidity level of 67%.
In contrast, April experiences slightly cooler temperatures, with a minimum of 21°C (71°F) and an average of 27°C (82°F), peaking at 35°C (95°F). The precipitation increases to 86 mm (3.4 in) spread over 14 days, leading to a higher humidity level of 92%. This makes April feel more humid and potentially more uncomfortable than December. For more detailed insights into the weather in April, you can check Oeiras weather in April.
In December, the weather is characterized by higher maximum temperatures, reaching up to 39°C (102°F), while the average temperature remains at a consistent 29°C (84°F). The month also experiences more precipitation, with 81 mm (3.2 in) over approximately 10 days, contributing to a relative humidity of 67%. In contrast, May features slightly lower maximum temperatures at 37°C (98°F) and maintains the same average of 29°C (84°F). However, it has significantly less rainfall, totaling just 13 mm (0.5 in) over 3 days, resulting in higher humidity levels at 87%. For more details on the weather in May, you can visit Oeiras weather in May.
December and June present distinct weather patterns, despite having similar average temperatures of 29°C (84°F). December experiences a wider temperature range, with minimums of 22°C (72°F) and maximums reaching 39°C (102°F). In contrast, June tends to be slightly cooler with a minimum of 20°C (69°F) and a maximum of 37°C (98°F). Precipitation levels also differ significantly; December sees about 81 mm (3.2 in) over approximately 10 days, while June boasts a much drier climate, with just 3 mm (0.1 in) of rain and no rainy days at all. Additionally, humidity in June is higher, at 77%, compared to December's 67%. For more detailed information, you can check Oeiras weather in June.
In December, temperatures in Oeiras range from a minimum of 22°C (72°F) to a maximum of 39°C (102°F), with an average temperature of 29°C (84°F). The month also sees about 81 mm (3.2 in) of rainfall spread across approximately 10 days, resulting in a humidity level of 67%. In contrast, July features slightly cooler temperatures, with a minimum of 21°C (70°F) and a maximum of 38°C (101°F), while maintaining the same average of 29°C (84°F). Notably, July is dry, with no recorded precipitation and a humidity level of 66%. For more detailed insights about Oeiras weather, you can check Oeiras weather in July.
In December, Oeiras experiences warmer temperatures, with a minimum of 22°C (72°F) and an average of 29°C (84°F), peaking at a maximum of 39°C (102°F). This month also brings higher humidity levels at 67% and an average of 81 mm (3.2 in) of precipitation over approximately 10 days, contributing to a more humid and wet climate. In contrast, August offers slightly cooler conditions, with temperatures ranging from a minimum of 20°C (68°F) to an average of 30°C (86°F) and a maximum of 38°C (101°F). Notably, August is significantly drier, with no recorded precipitation and lower humidity levels at 58%, making it a more comfortable month overall. For more detailed insights, you can check Oeiras weather in August.
In December, the weather is typically warm with temperatures ranging from a minimum of 22°C (72°F) to a maximum of 39°C (102°F), averaging around 29°C (84°F). The month experiences significant rainfall, with about 81 mm (3.2 inches) of precipitation spread over approximately 10 days, contributing to a humidity level of 67%. In contrast, September sees slightly cooler temperatures, with a minimum of 21°C (71°F) and a maximum of 40°C (104°F), averaging at 31°C (89°F). Notably, September is much drier, recording no precipitation at all and a lower humidity level of 51%. For more details, you can check Oeiras weather in September.
In December, temperatures range from a minimum of 22°C (72°F) to a maximum of 39°C (102°F), averaging around 29°C (84°F). This month sees a higher level of humidity at 67% and a significant increase in precipitation, with about 81 mm (3.2 in) over approximately 10 days. In contrast, October features slightly warmer temperatures, with minimums of 23°C (74°F), an average of 32°C (90°F), and maximums reaching 40°C (104°F). October is significantly drier, experiencing only 20 mm (0.8 in) of rain over just 2 days and enjoying lower humidity at 45%. For more in-depth information about October weather, you can visit Oeiras weather in October.
In December, temperatures remain quite stable, with a minimum of 22°C (72°F) and a maximum reaching 39°C (102°F), similar to November's range. However, the average temperature in December dips slightly to 29°C (84°F) compared to November's average of 30°C (86°F). Notably, December experiences higher precipitation, totaling 81 mm (3.2 in) over 10 days, while November sees only 51 mm (2.0 in) across 6 days. Humidity also rises significantly in December to 67%, in contrast to November's lower levels of 41%. For a detailed look at November's weather specifics, you can check Oeiras weather in November.
As December rolls into Oeiras, the weather becomes notably warmer compared to earlier months, pairing highs that can soar to a sweltering 39°C with an average temperature of 29°C. This shift fosters a vibrant, tropical atmosphere despite the 67% humidity that adds a touch of stickiness to the air. Although December experiences some rainfall, with about 10 days seeing 81 mm of precipitation, it still retains a more consistent warmth than the preceding months, making it an ideal time to enjoy the lush surroundings. For more detailed insights, take a look at the full Oeiras Climate.