September weather forecastSan Luis Obispo, CA
September
Weather in September
The first month of the autumn, September, is still a warm month in San Luis Obispo, California, with an average temperature varying between 79.9°F (26.6°C) and 60.3°F (15.7°C).Temperature
The advent of September presents an average high-temperature of a still moderately hot 79.9°F (26.6°C), maintaining a close correlation with the preceding month. During September, San Luis Obispo consistently records a temperature low averaging a refreshing 60.3°F (15.7°C).Humidity
September and October, with an average relative humidity of 57%, are the least humid months in San Luis Obispo.Rainfall
In San Luis Obispo, during September, the rain falls for 1.8 days and regularly aggregates up to 0.12" (3mm) of precipitation. Throughout the year, there are 57 rainfall days, and 9.57" (243mm) of precipitation is accumulated.Daylight
In San Luis Obispo, the average length of the day in September is 12h and 23min.On the first day of the month, sunrise is at 6:35 am and sunset at 7:29 pm. On the last day of September, sunrise is at 6:57 am and sunset at 6:47 pm PDT.
Sunshine
The average sunshine in September is 11.3h.UV index
In September, the average daily maximum UV index is 5. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV rays for the ordinary person.Note: The maximum UV index of 5 during September translates into these guidelines:
Preventative actions are necessary - Suggestions to safeguard against sun damage are in order. Midday is when the Sun's radiation is strongest; avoid prolonged exposure during this time. Counter UV radiation's ill effects with clothing designed for sun safety and UV-resistant eyewear.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
San Luis Obispo, CA
- Average high temperature in September: 79.9°F
The warmest month (with the highest average high temperature) is August (80.2°F).
The month with the lowest average high temperature is December (60.3°F).
- Average low temperature in September: 60.3°F
The month with the highest average low temperature is September (60.3°F).
The coldest month (with the lowest average low temperature) is February (45.7°F).
Average pressure in September
San Luis Obispo, CA
- Average pressure in September: 29.91"Hg
The month with the highest atmospheric pressure is January (30.12"Hg).
The months with the lowest atmospheric pressure are June, August and September (29.91"Hg).
Average wind speed in September
San Luis Obispo, CA
- Average wind speed in September: 5.3mph
The windiest months (with the highest average wind speed) are April and May (6.8mph).
The calmest months (with the lowest average wind speed) are August and September (5.3mph).
Average humidity in September
San Luis Obispo, CA
- Average humidity in September: 57%
The month with the highest relative humidity is March (69%).
The months with the lowest relative humidity are September and October (57%).
Average rainfall in September
San Luis Obispo, CA
- Average rainfall in September: 0.12"
The wettest month (with the highest rainfall) is March (2.01").
The driest months (with the least rainfall) are June and August (0.04").
Average rainfall days in September
San Luis Obispo, CA
- Average rainfall days in September: 1.8 days
The month with the highest number of rainy days is March (10.5 days).
The month with the least rainy days is August (0.6 days).
Average daylight in September /
Average sunshine in September
San Luis Obispo, CA
- Average daylight in September: 12h and 24min
The month with the longest days is June (Average daylight: 14h and 30min).
The month with the shortest days is December (Average daylight: 9h and 48min).
- Average sunshine in September: 11h and 18min
The months with the most sunshine are June, July and August (Average sunshine: 12h and 0min).
The months with the least sunshine are February and December (Average sunshine: 6h and 30min).
Average sunshine days in September
San Luis Obispo, CA
- Average sunshine days in September: 27.9 days
The month with the most sunshine days is August (29.2 days).
The month with the least sunshine days is February (19.1 days).
Average UV index in September
San Luis Obispo, CA
- Average UV index in September: 5
The months with the highest UV index are June and August (UV index 6).
The month with the lowest UV index is February (UV index 3).
Average cloud cover in September
San Luis Obispo, CA
- Average cloud cover in September: 6
The month with the most cloud cover is March (Cloud cover 28).
The months with the least cloud cover are August and September (Cloud cover 6).
Average visibility in September
San Luis Obispo, 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).
