World Resorts USA San Diego Weather

San Diego weather in September

Weather in San Diego: September

Average day temperature: 77.9°F
Average night temperature: 67.6°F
Sea water temperature: 69.0°F
Number of sunny days: 18 days
Day length: 11.9 - 12.8 hours
Number of rainy days: 0 days
Precipitation totals: 0.1 in.

Air temperature in September, °F

Show year:
2025
2024
2023

The highest day temperature during September of 2025 was 85°F. At the same time the lowest night temperature was 63°F. Daily and nightly averages during September were 76.9°F and 67.6°F.

Sea water temperature in San Diego in September, °F

Show year:
2025
2024
2023

The average sea water temperature in September of 2025 was 67.3°F. The highest and lowest sea temperatures during the month were 70.5°F and 63.1°F.

Sunny, partly cloudy and cloudy days

Mostly all days in September are sunny but cloudy days are also possible.

Precipitation total in September, in.

Precipitation total value in San Diego in September is 0.1 in. Other months of the year show relatively similar values.

Wind speed in September, mph

The average wind speed value in September is 6.3 mph

Average sunny hours

This chart shows average number of hours during the day when sunlight can reach the ground. It depends on day length and cloudiness during the day. The average number of sunny hours in September is: 7.5.

Best time for vacation in San Diego

Sunniest months:
July 21 days
June 20 days
August 20 days
Warmest months:
August 78.9 °F
September 77.9 °F
July 76.2 °F
Warmest sea temp:
August 69.9 °F
September 69.0 °F
July 68.8 °F
Coldest months:
January 63.2 °F
December 63.3 °F
February 63.3 °F
Rainiest months:
March 2 days
February 2 days
December 2 days
Windiest months:
May 7.5 mph
April 7.4 mph
March 7.2 mph

San Diego on a weather map

San Diego
+54°F
S 6 mph
Feels like: +52°F
Precip.: 0%
Places in USA:
Name
°F
+30°F
+75°F
+75°F
+41°F
+52°F
+70°F
+77°F
+70°F
+21°F
+54°F
+46°F
+61°F
+61°F
+45°F
+3°F
24 Hours Forecast
San Diego
Local time: 23:53
December 05, friday
0000
54°F
S
6 mph
0300
52°F
S
2 mph
0600
46°F
SW
1 mph
0900
52°F
SW
1 mph
1200
68°F
E
5 mph
1500
70°F
SE
8 mph
1800
64°F
E
7 mph
2100
59°F
SE
4 mph
Units of measurement: °C / °F