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
As August transitions into September, the average high-temperature rests at a still moderately hot 80.1°F (26.7°C), maintaining a close resemblance to the previous month. An average minimum temperature of 65.5°F (18.6°C) marks the month of September in San Ysidro.Humidity
The average relative humidity in September in San Ysidro, California, is 62%.Rainfall
In September, in San Ysidro, the rain falls for 4.5 days. Throughout September, 0.35" (9mm) of precipitation is accumulated. In San Ysidro, during the entire year, the rain falls for 57.8 days and collects up to 7.28" (185mm) of precipitation.Daylight
In September, the average length of the day is 12h and 21min.On the first day of the month, sunrise is at 6:23 am and sunset at 7:12 pm. On the last day of September, sunrise is at 6:42 am and sunset at 6:33 pm PDT.
Sunshine
In September, the average sunshine is 10.2h.UV index
June through September, with an average maximum UV index of 6, are months with the highest UV index in San Ysidro, California. A UV Index estimate of 6 to 7 represents a high health risk from exposure to the Sun's UV rays for the average person.Note: The maximum daily UV index of 6 in September interprets into the following recommendations:
Fend off overexposure. Sun protection is vital. The Sun's UV radiation is most potent between the hours of 10 a.m. and 4 p.m. Try to avoid direct sunlight during this time. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure.
Frequently asked questions
What is the temperature in September in San Ysidro?
What is the average humidity in September in San Ysidro?
How many days does it rain in September in San Ysidro?
What is the average length of the day in September in San Ysidro?
When are sunrise and sunset in September in San Ysidro?
How many hours of sunshine does San Ysidro have in September?
When is the highest UV index in San Ysidro?
What is the UV index reading in September in San Ysidro?
Average temperature in September
San Ysidro, CA
- Average high temperature in September: 80.1°F
The warmest month (with the highest average high temperature) is August (81.1°F).
The month with the lowest average high temperature is December (64°F).
- Average low temperature in September: 65.5°F
The month with the highest average low temperature is August (66.7°F).
The coldest month (with the lowest average low temperature) is February (50.2°F).
Average pressure in September
San Ysidro, CA
- Average pressure in September: 29.88"Hg
The month with the highest atmospheric pressure is January (30.08"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.88"Hg).
Average wind speed in September
San Ysidro, CA
- Average wind speed in September: 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 October (4.8mph).
Average humidity in September
San Ysidro, CA
- Average humidity in September: 62%
The month with the highest relative humidity is May (68%).
The month with the lowest relative humidity is November (55%).
Average rainfall in September
San Ysidro, CA
- Average rainfall in September: 0.35"
The wettest month (with the highest rainfall) is February (1.5").
The driest month (with the least rainfall) is June (0.08").
Average rainfall days in September
San Ysidro, CA
- Average rainfall days in September: 4.5 days
The month with the highest number of rainy days is March (7.5 days).
The month with the least rainy days is June (1.8 days).
Average daylight in September /
Average sunshine in September
San Ysidro, CA
- Average daylight in September: 12h and 2min
The month with the longest days is June (Average daylight: 14h and 18min).
The month with the shortest days is December (Average daylight: 10h and 6min).
- Average sunshine in September: 10h and 1min
The month with the most sunshine is July (Average sunshine: 12h and 0min).
The month with the least sunshine is December (Average sunshine: 6h and 36min).
Average sunshine days in September
San Ysidro, CA
- Average sunshine days in September: 24.3 days
The month with the most sunshine days is June (27.8 days).
The month with the least sunshine days is February (20.8 days).
Average UV index in September
San Ysidro, 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
San Ysidro, CA
- Average cloud cover in September: 12
The months with the most cloud cover are March and December (Cloud cover 25).
The month with the least cloud cover is August (Cloud cover 8).
Average visibility in September
San Ysidro, 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 Ysidro, California, USA
Weather forecast for your location
2. Allow the app to use your location
