September weather forecastRio Claro, Brazil

September

Weather in September

September, the first month of the spring in Rio Claro, is still a warm month, with an average temperature fluctuating between 28.9°C (84°F) and 16.4°C (61.5°F).

Temperature

The arrival of September brings an average high-temperature of a still warm 28.9°C (84°F), nearly identical to August's 26.3°C (79.3°F). Rio Claro experiences a significant downturn from peak daytime temperatures throughout September, with the average low-temperature dipping to a refreshing 16.4°C (61.5°F).

Heat index

In September, the heat index is appraised at a hot 31°C (87.8°F). Fatigue might occur with continuous exposure and activity, potentially causing heat cramps.
Realize that the values for the heat index are set for shaded places and light winds. Being exposed to direct sunshine might trigger a heat index increase by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'felt air temperature', is a fusion of air temperature and moisture levels to demonstrate the sensation of heat. Additional elements including metabolic differences, the level of physical activity, and attire have a role in shaping the individual's temperature perception. It is noteworthy to mention that direct sunlight exposure can augment the felt temperature, leading to an increase in the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are highly critical for babies and toddlers. Children frequently underestimate the necessity to rest and hydrate. Thirst is a late sign of dehydration - thus, it is vital to stay hydrated, particularly during lengthy physical exercises.

Humidity

With an average relative humidity of 63%, September is the least humid month in Rio Claro.

Rainfall

In September, in Rio Claro, Brazil, the rain falls for 9.8 days. Throughout September, 38mm (1.5") of precipitation is accumulated. Throughout the year, there are 185.9 rainfall days, and 870mm (34.25") of precipitation is accumulated.

Daylight

In September, the average length of the day in Rio Claro, Brazil, is 11h and 59min.
On the first day of the month, sunrise is at 06:19 and sunset at 18:00. On the last day of September, in Rio Claro, sunrise is at 05:51 and sunset at 18:08 -03.

Sunshine

The month with the most sunshine is September, with an average of 9.2h of sunshine.

UV index

January through March, August through November, with an average maximum UV index of 6, are months with the highest UV index in Rio Claro. A UV Index reading of 6 to 7 represents a high threat to health from exposure to the Sun's UV rays for the ordinary person.
Note: The UV index of 6 during September translates into the following guidance:
Exercise precautions and adapt sun safety practices. Defence against skin and eye affliction is paramount. The hours from 10 a.m. to 4 p.m. have the most intense UV radiation. As much as possible, limit direct sun exposure during this period. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses.

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

Frequently asked questions

In Rio Claro, 28.9°C (84°F) is the average high-temperature and 16.4°C (61.5°F) is the average low-temperature during September. In September, the average heat index (a.k.a. 'real feel', 'felt air temperature'), which combines relative humidity and air temperature, is appraised at 31°C (87.8°F).

September is the least humid month in Rio Claro, with an average relative humidity of 63%.

In September, the average relative humidity in Rio Claro, Brazil, is 63%.

In Rio Claro, Brazil, in September, it is raining for 9.8 days, with typically 38mm (1.5") of accumulated precipitation.

The average day length in September in Rio Claro is 11h and 59min.

On the first day of September in Rio Claro, Brazil, sunrise is at 06:19 and sunset at 18:00. On the last day of the month, sunrise is at 05:51 and sunset at 18:08 -03.

With an average of 9.2h of sunshine, September has the most sunshine of the year.

In September, the average sunshine duration is 9.2h.

January through March, August through November, with an average maximum UV index of 6, are months with the highest UV index in Rio Claro, Brazil.

In September, the average daily maximum UV index in Rio Claro is 6. A UV Index estimate of 6 to 7 represents a high health risk from exposure to Sun's UV rays.

Today

Tomorrow

Long-term

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

Aug

September

Oct

Average high temperature

26.3°C

28.9°C

29.4°C

Average low temperature

Average pressure

Average wind speed

Average max. wind speed

9.3km/h

10km/h

Average wind speed gusts

Average humidity

Average rainfall

Average rainfall days

Average daylight

Average sunshine

Average sunshine days

24.6

18.7

Average UV index

Average cloud cover

Average visibility

Average temperature in September
Rio Claro, Brazil

Average high temperature in September: 28.9°C

The warmest month (with the highest average high temperature) is October (29.4°C).
The month with the lowest average high temperature is June (22.8°C).

Average low temperature in September: 16.4°C

The month with the highest average low temperature is December (19.5°C).
The coldest month (with the lowest average low temperature) is June (13.4°C).

Average pressure in September
Rio Claro, Brazil

Average pressure in September: 1016.4mbar

The month with the highest atmospheric pressure is July (1020mbar).
The month with the lowest atmospheric pressure is December (1011.7mbar).

Average wind speed in September
Rio Claro, Brazil

Average wind speed in September: 8.8km/h

The windiest month (with the highest average wind speed) is October (8.9km/h).
The calmest months (with the lowest average wind speed) are March and April (6.5km/h).

Average humidity in September
Rio Claro, Brazil

Average humidity in September: 63%

The month with the highest relative humidity is March (86%).
The month with the lowest relative humidity is September (63%).

Average rainfall in September
Rio Claro, Brazil

Average rainfall in September: 38mm

The wettest month (with the highest rainfall) is January (154mm).
The driest month (with the least rainfall) is August (21mm).

Average rainfall days in September
Rio Claro, Brazil

Average rainfall days in September: 9.8 days

The month with the highest number of rainy days is January (25.9 days).
The month with the least rainy days is August (5.9 days).

Average daylight in September /
Average sunshine in September
Rio Claro, Brazil

Average daylight in September: 12h and 0min

The month with the longest days is December (Average daylight: 13h and 30min).
The month with the shortest days is June (Average daylight: 10h and 48min).

Average sunshine in September: 9h and 12min

The month with the most sunshine is September (Average sunshine: 9h and 12min).
The month with the least sunshine is January (Average sunshine: 7h and 6min).

Average sunshine days in September
Rio Claro, Brazil

Average sunshine days in September: 18.7 days

The month with the most sunshine days is August (24.6 days).
The month with the least sunshine days is January (4.3 days).

Average UV index in September
Rio Claro, Brazil

Average UV index in September: 6

The months with the highest UV index are January, February, March, August, September, October and November (UV index 6).
The months with the lowest UV index are April, May, June, July and December (UV index 5).

Average cloud cover in September
Rio Claro, Brazil

Average cloud cover in September: 24

The month with the most cloud cover is January (Cloud cover 54).
The month with the least cloud cover is August (Cloud cover 20).

Average visibility in September
Rio Claro, Brazil

Average visibility in September: 9km

The months with the highest visibility are July, August, September, October and November (9km).
The months with the lowest visibility are January, March, April and May (7km).