Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
During September, Monrovia observes a subtle ascent to a moderately hot 85.5°F (29.7°C) from August's 88.2°F (31.2°C) in the average high-temperature. Monrovia logs a substantial downturn to a comfortable 62.8°F (17.1°C) during September nights, a considerable shift from daytime highs.Heat index
For September, the heat index is evaluated at a tropical 86°F (30°C). Unrelenting activity during exposure could cause fatigue and potentially lead to heat cramps.Heat index's context suggests values are appropriate for shady areas and slight breezes. Being under direct sunlight might amplify the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'feels like' or 'real feel', is an aggregate value of air's warmth and moisture to show the human-felt temperature. Elements such as metabolic variations, pregnancy, and physical exertion can influence one's weather perception. Under direct sun rays, the felt temperature might be heightened, with the heat index increasing by 15 Fahrenheit (8 Celsius) degrees. Heat index values hold great significance to children. Typically, children face more danger than adults as they usually perspire less. Their larger skin surface relative to their small bodies and increased heat output from their activities enhance their risk.
Humidity
The average relative humidity in September in Monrovia, California, is 48%.Rainfall
In Monrovia, in September, it is raining for 2.6 days, with typically 0.12" (3mm) of accumulated precipitation. Throughout the year, in Monrovia, California, there are 50.9 rainfall days, and 8.46" (215mm) of precipitation is accumulated.Daylight
In September, the average length of the day in Monrovia is 12h and 22min.On the first day of September, sunrise is at 6:26 am and sunset at 7:17 pm. On the last day of the month, sunrise is at 6:46 am and sunset at 6:37 pm PDT.
Sunshine
In September, the average sunshine is 10.8h.UV index
The months with the highest UV index are June through September, with an average maximum UV index of 6. A UV Index value of 6 to 7 symbolizes a high health risk from exposure to the Sun's UV radiation for ordinary individuals.Note: A maximum high UV index of 6 in September translates into the following recommendations:
Use measures and accept sun safety conventions. Guarding against skin and eye trauma is of high priority. Attempt to stay under shade and limit exposure to the Sun between 10 a.m. and 4 p.m., when UV radiation is at its peak. Remember, devices such as parasols or canopies might not provide complete sun protection. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized.
Frequently asked questions
Is it hot in Monrovia during September?
What is the average humidity in September in Monrovia?
How many days does it rain in September in Monrovia?
How many hours of daylight does Monrovia have in September?
When is the sunrise / sunset in September in Monrovia?
How long on average sun shines in September in Monrovia?
What is the month with the highest UV index in Monrovia?
What is the UV index reading in September in Monrovia?
Average temperature in September
Monrovia, CA
- Average high temperature in September: 85.5°F
The warmest month (with the highest average high temperature) is August (88.2°F).
The month with the lowest average high temperature is December (61.7°F).
- Average low temperature in September: 62.8°F
The month with the highest average low temperature is August (64.8°F).
The coldest month (with the lowest average low temperature) is December (45.7°F).
Average pressure in September
Monrovia, CA
- Average pressure in September: 29.89"Hg
The month with the highest atmospheric pressure is January (30.11"Hg).
The month with the lowest atmospheric pressure is June (29.88"Hg).
Average wind speed in September
Monrovia, 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
Monrovia, CA
- Average humidity in September: 48%
The months with the highest relative humidity are March and May (56%).
The month with the lowest relative humidity is November (46%).
Average rainfall in September
Monrovia, CA
- Average rainfall in September: 0.12"
The wettest months (with the highest rainfall) are February and December (1.77").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
Monrovia, CA
- Average rainfall days in September: 2.6 days
The month with the highest number of rainy days is March (7.4 days).
The month with the least rainy days is June (1.1 days).
Average daylight in September /
Average sunshine in September
Monrovia, CA
- Average daylight in September: 12h and 2min
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 5min
The month with the most sunshine is July (Average sunshine: 12h and 6min).
The months with the least sunshine are January, February and December (Average sunshine: 6h and 54min).
Average sunshine days in September
Monrovia, CA
- Average sunshine days in September: 26.2 days
The month with the most sunshine days is June (28.3 days).
The month with the least sunshine days is February (21 days).
Average UV index in September
Monrovia, CA
- Average UV index in September: 6
The months with the highest UV index are June, July, August and September (UV index 6).
The month with the lowest UV index is December (UV index 3).
Average cloud cover in September
Monrovia, CA
- Average cloud cover in September: 7
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
Monrovia, 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).
Monrovia, California, USA
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