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
San Dimas's average high-temperature in September is a still hot 86.7°F (30.4°C), marking an insignificant difference from the 89.4°F (31.9°C) of August. San Dimas registers a prominent dip from daytime highs, with an average of 63.3°F (17.4°C) during the nights of September.Heat index
September's mean heat index is calculated to be a tropical 87.8°F (31°C). Exhaustion might be the outcome of enduring exposure and continuous activity, with a risk of heat cramps.Observations indicate that the heat index values are for shady locations with light wind. A direct sunlight exposure may boost the heat index by 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature' or 'feels like', blends air temperature and moisture content to represent the felt temperature to humans. The perception of temperature can be subjective, varying based on activity and individual heat sensitivity, influenced by factors like 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 particularly meaningful for babies and toddlers. Juveniles often do not understand the need to recuperate and rehydrate. Thirst is a delayed symptom of dehydration - hence, it is vital to maintain hydration, particularly during ongoing physical activities.
Humidity
In September, the average relative humidity in San Dimas is 46%.Rainfall
In San Dimas, during September, the rain falls for 2.5 days and regularly aggregates up to 0.12" (3mm) of precipitation. In San Dimas, during the entire year, the rain falls for 45.2 days and collects up to 6.5" (165mm) of precipitation.Daylight
In San Dimas, the average length of the day in September 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, in San Dimas, sunrise is at 6:45 am and sunset at 6:36 pm PDT.
Sunshine
In September, the average sunshine is 10.7h.UV index
In San Dimas, the average daily maximum UV index in September is 6. A UV Index of 6 to 7 symbolizes a high health risk from unprotected exposure to Sun's UV rays for average individuals.Note: The UV index of 6 during September leads to these advisories:
Adhere to precautions and respect sun safety doctrines. Avoiding sunburn is vital. Seek shade and minimize exposure to direct Sun in a period between 10 a.m. and 4 p.m. when UV radiation is most intense; keep in mind that shade structures like parasols or canopies do not provide perfect sun protection. Equip yourself with UVA and UVB-filtering sunglasses on clear, sunny days.
Frequently asked questions
How hot does it get in San Dimas in September?
What is the average humidity in September in San Dimas?
How many days does it rain in September in San Dimas?
What is the average length of the day in September in San Dimas?
What time are sunrise and sunset in September in San Dimas?
How long on average sun shines in September in San Dimas?
What is the UV index intensity in September in San Dimas?
Average temperature in September
San Dimas, CA
- Average high temperature in September: 86.7°F
The warmest month (with the highest average high temperature) is August (89.4°F).
The month with the lowest average high temperature is December (62.4°F).
- Average low temperature in September: 63.3°F
The month with the highest average low temperature is August (64.9°F).
The coldest month (with the lowest average low temperature) is December (45.5°F).
Average pressure in September
San Dimas, CA
- Average pressure in September: 29.88"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.87"Hg).
Average wind speed in September
San Dimas, CA
- Average wind speed in September: 4.3mph
The windiest months (with the highest average wind speed) are April and May (5.7mph).
The calmest month (with the lowest average wind speed) is September (4.3mph).
Average humidity in September
San Dimas, CA
- Average humidity in September: 46%
The months with the highest relative humidity are March and May (55%).
The months with the lowest relative humidity are August and November (45%).
Average rainfall in September
San Dimas, CA
- Average rainfall in September: 0.12"
The wettest month (with the highest rainfall) is February (1.46").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
San Dimas, CA
- Average rainfall days in September: 2.5 days
The month with the highest number of rainy days is March (6.3 days).
The month with the least rainy days is June (1.2 days).
Average daylight in September /
Average sunshine in September
San Dimas, 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 4min
The months with the most sunshine are June and July (Average sunshine: 12h and 6min).
The months with the least sunshine are January, February and December (Average sunshine: 7h and 0min).
Average sunshine days in September
San Dimas, CA
- Average sunshine days in September: 25.5 days
The month with the most sunshine days is June (27.8 days).
The month with the least sunshine days is February (22 days).
Average UV index in September
San Dimas, CA
- Average UV index in September: 6
The months with the highest UV index are July and August (UV index 7).
The month with the lowest UV index is December (UV index 3).
Average cloud cover in September
San Dimas, CA
- Average cloud cover in September: 6
The months with the most cloud cover are March and December (Cloud cover 21).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility in September
San Dimas, 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).
San Dimas, California, USA
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