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 snowfall 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
Grand Terrace transitions into September recording an average high-temperature of a still hot 87.4°F (30.8°C), closely aligning with the preceding month's temperature. Throughout September, Grand Terrace notes a dramatic plunge from the daily high to an average low-temperature of 63.3°F (17.4°C).Heat index
For September, the heat index is calculated to be a tropical 87.8°F (31°C). Enduring exposure and ongoing activity could cause a sense of fatigue and subsequent heat cramps.One should be cognizant that the heat index values are tailored for shaded spots and mild winds. The heat index might be elevated by 15 Fahrenheit (8 Celsius) degrees due to direct sun exposure.
Note: The heat index, also known as 'felt air temperature' or 'apparent temperature', determines the feeling of heat when you account for the relative humidity. Physical activity, clothing, and metabolic variations are additional factors that impact an individual's perception of temperature. With the sun shining directly, it's crucial to understand that it can increase the heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are quite important for children. Children regularly disregard the necessity to rest and replenish fluids. Thirst is a late symptom of dehydration - thus, maintaining hydration, particularly during long-lasting physical activities, is essential.
Humidity
The average relative humidity in September is 41%.Rainfall
In Grand Terrace, in September, it is raining for 1.9 days, with typically 0.08" (2mm) of accumulated precipitation. In Grand Terrace, during the entire year, the rain falls for 46.6 days and collects up to 6.18" (157mm) of precipitation.Snowfall
In Grand Terrace, snow does not fall in January, March through December.Daylight
In September, the average length of the day is 12h and 22min.On the first day of September, sunrise is at 6:23 am and sunset at 7:14 pm. On the last day of the month, sunrise is at 6:43 am and sunset at 6:34 pm PDT.
Sunshine
In September, the average sunshine is 10.7h.UV index
In Grand Terrace, the average daily maximum UV index in September is 6. A UV Index estimate of 6 to 7 represents a high health risk from exposure to the Sun's UV rays for average individuals.Note: The average daily UV index of 6 in September transforms into the following instructions:
Avoid overexposure. Fair-skinned individuals can burn in under 20 minutes. Stay out of direct sunlight and seek shade between 10 a.m. and 4 p.m., when UV radiation is strongest, but remember that shade devices may not offer full sun protection. Always opt for UVA and UVB-resistant sunglasses on radiant days.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Is it hot during September?
What is the average humidity in September?
How many days does it rain in September?
When it does not snow?
How many hours of daylight does Grand Terrace have in September?
What time are sunrise and sunset in September?
How many hours of sunshine does Grand Terrace have in September?
What is the UV index reading in September?
Average temperature in September
Grand Terrace, CA
- Average high temperature in September: 87.4°F
The warmest month (with the highest average high temperature) is August (91.9°F).
The month with the lowest average high temperature is December (59.9°F).
- Average low temperature in September: 63.3°F
The month with the highest average low temperature is August (65.8°F).
The coldest month (with the lowest average low temperature) is February (43.5°F).
Average pressure in September
Grand Terrace, CA
- Average pressure in September: 29.87"Hg
The month with the highest atmospheric pressure is January (30.1"Hg).
The month with the lowest atmospheric pressure is June (29.85"Hg).
Average wind speed in September
Grand Terrace, CA
- Average wind speed in September: 4.5mph
The windiest months (with the highest average wind speed) are April and May (6mph).
The calmest month (with the lowest average wind speed) is September (4.5mph).
Average humidity in September
Grand Terrace, CA
- Average humidity in September: 41%
The month with the highest relative humidity is February (53%).
The month with the lowest relative humidity is August (38%).
Average rainfall in September
Grand Terrace, CA
- Average rainfall in September: 0.08"
The wettest month (with the highest rainfall) is December (1.42").
The driest month (with the least rainfall) is June (0.04").
Average rainfall days in September
Grand Terrace, CA
- Average rainfall days in September: 1.9 days
The month with the highest number of rainy days is March (6.7 days).
The month with the least rainy days is June (1.2 days).
Average snowfall days in September
Grand Terrace, CA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (0.1 days).
The months with the least snowfall days are January, March, April, May, June, July, August, September, October, November and December (0 days).
Average daylight in September /
Average sunshine in September
Grand Terrace, 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 month with the most sunshine is July (Average sunshine: 12h and 12min).
The month with the least sunshine is December (Average sunshine: 6h and 54min).
Average sunshine days in September
Grand Terrace, CA
- Average sunshine days in September: 26.7 days
The months with the most sunshine days are June and October (27.9 days).
The month with the least sunshine days is February (21.7 days).
Average UV index in September
Grand Terrace, CA
- Average UV index in September: 6
The months with the highest UV index are June, July and August (UV index 7).
The month with the lowest UV index is December (UV index 3).
Average cloud cover in September
Grand Terrace, CA
- Average cloud cover in September: 6
The months with the most cloud cover are February and December (Cloud cover 21).
The month with the least cloud cover is August (Cloud cover 5).
Average visibility in September
Grand Terrace, 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).
Grand Terrace, California, USA
Weather forecast for your location
2. Allow the app to use your location