September weather forecastCastanhal, Brazil

September

Weather in September

The first month of the spring, September, is also a hot month in Castanhal, Brazil, with an average temperature ranging between max 32.9°C (91.2°F) and min 22.1°C (71.8°F).

Temperature

Castanhal sees the arrival of September with an average high-temperature of a still hot 32.9°C (91.2°F), indicating a subtle variation from August. Castanhal records an average temperature drop to a pleasant 22.1°C (71.8°F) in September.

Heat index

The heat index in September is calculated to be a burning hot 47°C (116.6°F). Prudent: Heat cramps and heat exhaustion are likely. Heatstroke becomes imminent with sustained exertion.
Metrics for the heat index primarily focus on shaded spots and light wind conditions. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'real feel' or 'apparent temperature', embodies the combination of air temperature and moisture content to illustrate perceived heat. The effect is experienced differently by individuals, hinging on unique characteristics such as body mass, stature, and level of activity. Recognize that direct exposure to the sun can escalate the heat effect, potentially adding 15 Fahrenheit (8 Celsius) degrees to the heat index. Heat index values hold particular importance for children. Younglings are generally more in peril than adults due to their reduced perspiration. Coupled with a larger skin surface relative to their tiny bodies and greater heat production because of their activity, they become more at risk.
Sweat evaporation plays a crucial role in cooling the human body, a process enabled by perspiration. High relative humidity reduces the evaporation rate, resulting in a lower heat removal rate from the body, causing the perception of being overheated. Rising body temperatures due to excess heat retention could signify impending heat disorders.

Humidity

In September, the average relative humidity in Castanhal is 79%.

Rainfall

The month with the least rainfall in Castanhal is September, when the rain falls for 24.7 days and typically collects 45mm (1.77") of precipitation.

Daylight

In September, the average length of the day is 12h and 7min.
On the first day of September in Castanhal, sunrise is at 06:08 and sunset at 18:14. On the last day of the month, sunrise is at 05:57 and sunset at 18:05 -03.

Sunshine

In September, the average sunshine in Castanhal is 8.2h.

UV index

The months with the highest UV index in Castanhal are May, July, September through November, with an average maximum UV index of 7. A UV Index of 6 to 7 symbolizes a high health hazard from exposure to the Sun's UV rays for the average person.
Note: The UV index of 7 during September leads to these advisories:
Inhibit overexposure. Warding off sun damage is of utmost importance. Limit your exposure to the sun's UV radiation, which is strongest between 10 a.m. and 4 p.m., and note that parasols or canopies may not provide full sun protection. Tightly woven clothing, when worn loosely, shields effectively against the Sun.

Updated: Feb 2, 2024
Published by: Weather Atlas | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

In Castanhal, in September, the average high-temperature is 32.9°C (91.2°F), and the average low-temperature is 22.1°C (71.8°F). The average heat index (a.k.a. 'apparent temperature', 'felt air temperature'), which takes the relative humidity and factors it into the air temperature reading, in September is calculated to be 47°C (116.6°F).

The average relative humidity in September in Castanhal, Brazil, is 79%.

September is the month with the least rainfall in Castanhal. Rain falls for 24.7 days and accumulates 45mm (1.77") of precipitation.

In Castanhal, in September, it is raining for 24.7 days, with typically 45mm (1.77") of accumulated precipitation.

In September, the average day length in Castanhal is 12h and 7min.

On the first day of September in Castanhal, Brazil, sunrise is at 06:08 and sunset at 18:14. On the last day of the month, sunrise is at 05:57 and sunset at 18:05 -03.

In Castanhal, Brazil, the average sunshine duration in September is 8.2h.

May, July, September through November, with an average maximum UV index of 7, are months with the highest UV index.

In Castanhal, Brazil, the average daily maximum UV index in September is 7. A UV Index of 6 to 7 symbolizes a high health vulnerability from exposure to the Sun's UV radiation.

Today

Tomorrow

Long-term

Year J F M A M J J A September O N D

Aug

September

Oct

Average high temperature

32.5°C

32.9°C

33.5°C

Average low temperature

Average pressure

Average wind speed

Average max. wind speed

7km/h

7.2km/h

7.5km/h

Average wind speed gusts

Average humidity

Average rainfall

Average rainfall days

Average daylight

Average sunshine

Average sunshine days

2.5

3.9

5.4

Average UV index

Average cloud cover

Average visibility

Average temperature in September
Castanhal, Brazil

Average high temperature in September: 32.9°C

The warmest months (with the highest average high temperature) are October and November (33.5°C).
The months with the lowest average high temperature are March and April (29.7°C).

Average low temperature in September: 22.1°C

The month with the highest average low temperature is December (23°C).
The coldest month (with the lowest average low temperature) is July (21.5°C).

Average pressure in September
Castanhal, Brazil

Average pressure in September: 1011.7mbar

The month with the highest atmospheric pressure is July (1012.7mbar).
The month with the lowest atmospheric pressure is November (1009.2mbar).

Average wind speed in September
Castanhal, Brazil

Average wind speed in September: 6.9km/h

The windiest months (with the highest average wind speed) are September, October and November (6.9km/h).
The calmest month (with the lowest average wind speed) is April (4.8km/h).

Average humidity in September
Castanhal, Brazil

Average humidity in September: 79%

The month with the highest relative humidity is April (92%).
The month with the lowest relative humidity is November (76%).

Average rainfall in September
Castanhal, Brazil

Average rainfall in September: 45mm

The wettest month (with the highest rainfall) is March (252mm).
The driest month (with the least rainfall) is September (45mm).

Average rainfall days in September
Castanhal, Brazil

Average rainfall days in September: 24.7 days

The month with the highest number of rainy days is March (30.8 days).
The month with the least rainy days is November (22.2 days).

Average daylight in September /
Average sunshine in September
Castanhal, Brazil

Average daylight in September: 12h and 6min

The month with the longest days is December (Average daylight: 12h and 12min).
The month with the shortest days is June (Average daylight: 12h and 0min).

Average sunshine in September: 8h and 12min

The month with the most sunshine is August (Average sunshine: 8h and 36min).
The month with the least sunshine is March (Average sunshine: 5h and 36min).

Average sunshine days in September
Castanhal, Brazil

Average sunshine days in September: 3.9 days

The month with the most sunshine days is November (6 days).
The months with the least sunshine days are March and April (0 days).

Average UV index in September
Castanhal, Brazil

Average UV index in September: 7

The months with the highest UV index are May, July, September, October and November (UV index 7).
The months with the lowest UV index are January, February, March, April, June, August and December (UV index 6).

Average cloud cover in September
Castanhal, Brazil

Average cloud cover in September: 45

The months with the most cloud cover are March and April (Cloud cover 71).
The months with the least cloud cover are October and November (Cloud cover 44).