September weather forecastPlacentia, CA
September
Weather in September
September, the first month of the autumn in Placentia, is also a moderately hot month, with an average temperature fluctuating between 84°F (28.9°C) and 64.8°F (18.2°C).Temperature
September brings an average high-temperature of a still moderately hot 84°F (28.9°C), showing a slight difference from August's 85.3°F (29.6°C). Placentia temperatures generally rest at a low of 64.8°F (18.2°C) during the September nights.Heat index
The heat index for September is estimated at a tropical 86°F (30°C). Exhaustion becomes probable with enduring exposure and activity, potentially causing heat cramps.In the scope of the heat index, its values resonate with shade and light wind conditions. Exposure to direct sunlight may make the heat index values climb by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'felt air temperature' or 'real feel', gives a temperature feeling by integrating air temperature and humidity. This effect is personal, influenced by the individual's physical activity and heat sensitivity, shaped by factors including wind, attire, and metabolic variations. Direct sunlight exposure should be noted as it has the potential to increase the heat index by 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Kids often lack the knowledge about the necessity to take breaks and consume liquids. Thirst, as a late symptom of dehydration, necessitates the maintenance of hydration, particularly during enduring physical activities.
Humidity
In Placentia, the average relative humidity in September is 56%.Rainfall
In September, the rain falls for 3 days. Throughout September, 0.16" (4mm) of precipitation is accumulated. In Placentia, during the entire year, the rain falls for 53.2 days and collects up to 7.72" (196mm) of precipitation.Daylight
In September, the average length of the day is 12h and 22min.On the first day of the month, sunrise is at 6:25 am and sunset at 7:16 pm. On the last day of September, sunrise is at 6:45 am and sunset at 6:36 pm PDT.
Sunshine
The average sunshine in September is 10.7h.UV index
June through September, with an average maximum UV index of 6, are months with the highest UV index. A UV Index estimate of 6 to 7 represents a high threat to health from unsafe exposure to UV radiation for average individuals.Note: During September, 6 as the daily maximum UV index converts into the following advice:
Adhere to precautions and respect sun safety doctrines. Avoiding sunburn is vital. Limit direct sun exposure especially between 10 a.m. and 4 p.m., when UV radiation is at its peak. However, keep in mind that shade structures may not provide full sun protection. It's wise to wear UVA and UVB-blocking sunglasses when the sun shines brightly.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Placentia, CA
- Average high temperature in September: 84°F
The warmest month (with the highest average high temperature) is August (85.3°F).
The month with the lowest average high temperature is December (64.2°F).
- Average low temperature in September: 64.8°F
The month with the highest average low temperature is August (65.7°F).
The coldest month (with the lowest average low temperature) is February (49.6°F).
Average pressure in September
Placentia, CA
- Average pressure in September: 29.89"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in September
Placentia, CA
- Average wind speed in September: 4.5mph
The windiest month (with the highest average wind speed) is April (5.8mph).
The calmest month (with the lowest average wind speed) is September (4.5mph).
Average humidity in September
Placentia, CA
- Average humidity in September: 56%
The month with the highest relative humidity is June (63%).
The month with the lowest relative humidity is November (50%).
Average rainfall in September
Placentia, CA
- Average rainfall in September: 0.16"
The wettest month (with the highest rainfall) is December (1.65").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
Placentia, CA
- Average rainfall days in September: 3 days
The month with the highest number of rainy days is March (7.4 days).
The month with the least rainy days is June (1.4 days).
Average daylight in September /
Average sunshine in September
Placentia, CA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 24min).
The month with the shortest days is December (Average daylight: 9h and 54min).
- Average sunshine in September: 10h and 42min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The months with the least sunshine are February and December (Average sunshine: 6h and 48min).
Average sunshine days in September
Placentia, CA
- Average sunshine days in September: 24.4 days
The month with the most sunshine days is August (26.7 days).
The month with the least sunshine days is February (20.7 days).
Average UV index in September
Placentia, CA
- Average UV index in September: 6
The months with the highest UV index are June, July, August and September (UV index 6).
The months with the lowest UV index are January, February, November and December (UV index 4).
Average cloud cover in September
Placentia, CA
- Average cloud cover in September: 8
The months with the most cloud cover are March and December (Cloud cover 22).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility in September
Placentia, CA
- Average visibility in September: 6mi
The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
