San Diego at a glance
- Best time
- Jul – Sep
- Warmest month
- Aug · 26°
- Warmest sea
- Aug · 21.0°
- Sunshine a year
- 3,530 h
- Rain a year
- 335 mm
- Climate
- Mediterranean
- Time zone
- UTC−8 / UTC−7
- Elevation
- 20 m
Climate in San Diego
San Diego has a Mediterranean climate with warm to hot, dry summers and mild, wetter winters. August is the warmest month with average highs of 26 °C, while February is the coolest at 17 °C. With around 3,530 hours of sunshine a year, San Diego is very sunny; July is the sunniest month with 11.7 hours a day.
Holiday weather through the year
Weather in October
Holiday weather in October
Good
Best time to visit: July – September
What is the weather like in San Diego in October?
In October, San Diego is warm: daytime highs average 23 °C, and nights cool down to about 15 °C. The sea averages 19.2 °C – bracing, so a wetsuit helps for longer swims. With around 9 hours of sunshine a day, there is plenty of sun. Rain is rare: about 2 days bring 17 mm in total. All in all, October is a good month for a holiday in San Diego.
More details for October
- Daylight
- 11 h 25 min06:52 – 18:17
- UV index
- 6 · highclear sky, noon (estimate)All months
- Muggy days
- 1 daydew point 18 °C or more
- Wind
- 16 km/haverage daily peak
- Cloud cover
- 34 %on average
- Hot days
- 1 day30 °C or more
- Time zone
- UTC−7America/Los_Angeles
How the score comes together
- Temperatureweight 35 %68 %
- Seaweight 25 %31 %
- Sunshineweight 20 %100 %
- Few rainy daysweight 20 %100 %
Each factor is rated from 0 to 100 % and weighted for the travel style “Sun, sea & sand”.
What to pack in October
- Wetsuit for longer swims
- Sunscreen
- Sunglasses & sun hat
- A jumper for the evenings
Sea temperature in San Diego
Monthly sea surface temperature with the range of cooler and warmer years.
8 in 10 years: 18.2 – 20.6 °C
Swimming season: Jul – Sep
- cold
- fresh
- refreshing
- pleasant
- warm
- very warm
The sea temperature in San Diego ranges from 15.0 °C in February to 21.0 °C in August. It is warm enough for a comfortable swim (20 °C and more) from July to September.
The sea temperature varies from year to year: in August, eight out of ten years were between 19.7 and 22.4 °C.
| Month | Average | Cool year | Warm year | Feels |
|---|---|---|---|---|
| JanuaryJan | 15.2° | 14.5° | 16.2° | cold |
| FebruaryFeb | 15.0° | 14.2° | 15.8° | cold |
| MarchMar | 15.3° | 14.4° | 16.4° | cold |
| AprilApr | 16.0° | 14.9° | 17.0° | cold |
| MayMay | 17.4° | 16.1° | 18.5° | fresh |
| JuneJun | 18.7° | 17.5° | 19.6° | fresh |
| JulyJul | 20.3° | 19.4° | 21.9° | refreshing |
| AugustAug | 21.0° | 19.7° | 22.4° | refreshing |
| SeptemberSep | 20.6° | 18.7° | 21.9° | refreshing |
| OctoberOct | 19.2° | 18.2° | 20.6° | fresh |
| NovemberNov | 17.4° | 16.5° | 18.8° | fresh |
| DecemberDec | 16.0° | 15.0° | 17.4° | cold |
Sunshine hours in San Diego
Average hours of bright sunshine per day, next to the length of the day. Tap a month to select it.
In October, the sun shines for about 9.4 of 11.4 hours of daylight in San Diego, 82 % of the day.
Sunshine hours count the time with bright, direct sunshine (WMO definition, estimated from model data); daylight is the time from sunrise to sunset on the 15th of the month.
UV index in San Diego
How strong the sun is at noon, month by month, and how quickly unprotected skin burns.
- Clear-sky UV in October
- 6 · highSeek shade around midday; sunscreen SPF 30+, hat and sunglasses.
The sun is strongest in June (UV 11).
Minutes until sunburn in October
- Very fair skin
- about 25 min
- Fair skin
- about 30 min
- Light brown skin
- about 40 min
- Olive skin
- about 50 min
Rough guide for unprotected skin at noon under a clear sky; clouds lengthen it, water, sand and snow shorten it. Sunscreen extends the time only partly.
Monthly values: clear-sky noon estimate from the sun's angle, ozone and altitude. UV today: Open-Meteo forecast.
Rain in San Diego: rainy days and rainfall
A rainy day is a day with at least 1 mm of rain or snow; the amount is what falls in the whole month. Tap a month to select it.
In October, San Diego has about 2 rainy days with 17 mm of rain in total.
Climate through the year
Long-term monthly averages. Tap a month to see its details.
Temperatures through the year
Average daytime high, night-time low and sea temperature per month.
| Month | Score | Day | Night | Sea | Sun | Rain days | Rain mm |
|---|---|---|---|---|---|---|---|
| JanuaryJan | 34 | 17° | 9° | 15.2° | 7.9 h | 6 | 56 |
| FebruaryFeb | 33 | 17° | 9° | 15.0° | 8.0 h | 7 | 78 |
| MarchMar | 37 | 18° | 10° | 15.3° | 9.2 h | 6 | 49 |
| AprilApr | 40 | 19° | 12° | 16.0° | 10.0 h | 4 | 24 |
| MayMay | 48 | 20° | 14° | 17.4° | 10.3 h | 2 | 12 |
| JuneJun | 64 | 22° | 15° | 18.7° | 11.5 h | 0 | 2 |
| JulyJul | 83 | 24° | 17° | 20.3° | 11.7 h | 1 | 2 |
| AugustAug | 89 | 26° | 18° | 21.0° | 11.5 h | 0 | 2 |
| SeptemberSep | 88 | 25° | 18° | 20.6° | 10.4 h | 1 | 5 |
| OctoberOct | 72 | 23° | 15° | 19.2° | 9.4 h | 2 | 17 |
| NovemberNov | 48 | 20° | 12° | 17.4° | 8.6 h | 4 | 33 |
| DecemberDec | 33 | 17° | 9° | 16.0° | 7.5 h | 6 | 54 |
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, GeoNames (CC BY 4.0)
32.72° N, 117.16° W · 20 m · America/Los_Angeles
Best time to visit San Diego
The best time to visit San Diego is from July to September. For a beach holiday with the sea above 21 °C, go in August. For sightseeing, day trips and hiking, the weather is pleasant all year round. The wettest month is February with 78 mm of precipitation.
San Diego through the seasons
How the weather changes over the seasons, with averages for each.
San Diego in spring
Mar – May
Fair
- 18–20 °C by day
- Sea 16 °C
- 10 h of sun a day
- 11 rainy days in all
San Diego in summer
Jun – Aug
Good
- 22–26 °C by day
- Sea 20 °C
- 12 h of sun a day
- 1 rainy days in all
San Diego in autumn
Sep – Nov
Good
- 20–25 °C by day
- Sea 19 °C
- 10 h of sun a day
- 7 rainy days in all
San Diego in winter
Dec – Feb
Poor
- 17 °C by day
- Sea 15 °C
- 8 h of sun a day
- 18 rainy days in all
Find your perfect month
Tell us what you like and we rate every month in San Diego for you.
Your best months: July – September
Based on the climate averages; tap a month to see its details.
Which month for what?
Beach & swimming
Aug
Sea from 21 °C, warm and mostly dry
Sightseeing & hiking
All year
15–28 °C and not too much rain
San Diego month by month
The typical weather for every month at a glance.
34January17° · Sea 15° · 8 h
In January, San Diego is mild: daytime highs average 17 °C, and nights cool down to about 9 °C. The sea averages 15.2 °C – swimming is only for the hardy. The sun shines for around 8 hours a day. Rain falls on about 6 days, adding up to 56 mm. All in all, January is not an ideal month for a holiday in San Diego.
San Diego in January33February17° · Sea 15° · 8 h
In February, San Diego is mild: daytime highs average 17 °C, and nights cool down to about 9 °C. The sea averages 15.0 °C – swimming is only for the hardy. The sun shines for around 8 hours a day. Rain falls on about 7 days, adding up to 78 mm. All in all, February is not an ideal month for a holiday in San Diego.
San Diego in February37March18° · Sea 15° · 9 h
In March, San Diego is mild: daytime highs average 18 °C, and nights cool down to about 10 °C. The sea averages 15.3 °C – swimming is only for the hardy. With around 9 hours of sunshine a day, there is plenty of sun. Rain falls on about 6 days, adding up to 49 mm. All in all, March is not an ideal month for a holiday in San Diego.
San Diego in March40April19° · Sea 16° · 10 h
In April, San Diego is mild: daytime highs average 19 °C, and nights cool down to about 12 °C. The sea averages 16.0 °C – swimming is only for the hardy. With around 10 hours of sunshine a day, there is plenty of sun. Rain is rare: about 4 days bring 24 mm in total. All in all, April is a so-so month for a holiday in San Diego.
San Diego in April48May20° · Sea 17° · 10 h
In May, San Diego is mild: daytime highs average 20 °C, and nights cool down to about 14 °C. The sea averages 17.4 °C – bracing, so a wetsuit helps for longer swims. With around 10 hours of sunshine a day, there is plenty of sun. It hardly ever rains. All in all, May is a so-so month for a holiday in San Diego.
San Diego in May64June22° · Sea 19° · 12 h
In June, San Diego is warm: daytime highs average 22 °C, and nights cool down to about 15 °C. The sea averages 18.7 °C – bracing, so a wetsuit helps for longer swims. With around 12 hours of sunshine a day, there is plenty of sun. It hardly ever rains. All in all, June is a good month for a holiday in San Diego.
San Diego in June83July24° · Sea 20° · 12 h
In July, San Diego is warm: daytime highs average 24 °C, and nights cool down to about 17 °C. The sea averages 20.3 °C – refreshing for a swim. With around 12 hours of sunshine a day, there is plenty of sun. It hardly ever rains. All in all, July is an excellent month for a holiday in San Diego.
San Diego in July89August26° · Sea 21° · 12 h
In August, San Diego is warm: daytime highs average 26 °C, and nights cool down to about 18 °C. The sea averages 21.0 °C – refreshing for a swim. With around 12 hours of sunshine a day, there is plenty of sun. It hardly ever rains. All in all, August is an excellent month for a holiday in San Diego.
San Diego in August88September25° · Sea 21° · 10 h
In September, San Diego is warm: daytime highs average 25 °C, and nights cool down to about 18 °C. The sea averages 20.6 °C – refreshing for a swim. With around 10 hours of sunshine a day, there is plenty of sun. It hardly ever rains. All in all, September is an excellent month for a holiday in San Diego.
San Diego in September72October23° · Sea 19° · 9 h
In October, San Diego is warm: daytime highs average 23 °C, and nights cool down to about 15 °C. The sea averages 19.2 °C – bracing, so a wetsuit helps for longer swims. With around 9 hours of sunshine a day, there is plenty of sun. Rain is rare: about 2 days bring 17 mm in total. All in all, October is a good month for a holiday in San Diego.
San Diego in October48November20° · Sea 17° · 9 h
In November, San Diego is mild: daytime highs average 20 °C, and nights cool down to about 12 °C. The sea averages 17.4 °C – bracing, so a wetsuit helps for longer swims. The sun shines for around 9 hours a day. Rain is rare: about 4 days bring 33 mm in total. All in all, November is a so-so month for a holiday in San Diego.
San Diego in November33December17° · Sea 16° · 8 h
In December, San Diego is mild: daytime highs average 17 °C, and nights cool down to about 9 °C. The sea averages 16.0 °C – swimming is only for the hardy. The sun shines for around 8 hours a day. Rain falls on about 6 days, adding up to 54 mm. All in all, December is not an ideal month for a holiday in San Diego.
San Diego in DecemberSan Diego compared
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San Diego vs. Los Angeles
In October Los Angeles has the better holiday weather (score 82 vs. 72). During the day Los Angeles is 3 °C warmer than San Diego. The sea is about equally warm. Los Angeles gets one more hour of sunshine a day.
| in October | San Diego | Los Angeles |
|---|---|---|
| Holiday score | 72 | 82 |
| Daytime high | 23° | 26° |
| Sea | 19° | 19° |
| Sunshine | 9 h | 10 h |
| Rainy days | 2 | 2 |
| Best time | Jul – Sep | Sep – Jul |
Through the year
USA in October: the best places
In October, San Diego ranks 10 of 10 destinations in this country.
- Los Angeles26°19°100
- 2Las Vegas26°100
- 3San Francisco21°14°99
- 4Kihei29°27°99
- 5Honolulu27°27°95
- 6Key West27°28°84
- 7Miami Beach28°28°80
- 8New York18°18°80
- 10San DiegoThis page23°19°72
Planning a trip to San Diego
Getting there
Flying from
- Nonstop flight
- about 11 h 5 min
- Distance
- 8,810 km
- Time zone
- UTC−7
Estimated from the straight-line distance: 30 minutes for take-off and landing plus 830 km/h cruising speed.
Frequently asked questions about San Diego
When is the best time to visit San Diego?
The best time to visit San Diego is from July to September. That is when the holiday weather score, which combines temperature, sea, sunshine and rain, is highest.
How warm is the sea in San Diego?
The sea temperature in San Diego ranges from 15.0 °C in February to 21.0 °C in August. It is warm enough for a comfortable swim (20 °C and more) from July to September.
Can you swim in San Diego in October?
Only if you don't mind cold water: in October the sea averages just 19.2 °C. Comfortable swimming is possible from July to September.
What is the warmest month in San Diego?
August is the warmest month, with average highs of 26 °C and nights around 18 °C. February is the coolest month at 17 °C.
When does it rain most in San Diego?
The wettest month is February with 78 mm of precipitation. The driest month is June with 2 mm.
How many hours of sunshine does San Diego get?
San Diego gets around 3,530 hours of sunshine a year. The sunniest month is July with 11.7 hours a day; in December there are 7.5 hours a day.
What time zone is San Diego in?
San Diego uses the time zone America/Los_Angeles: UTC−8 in January and UTC−7 in July.
How long is the flight from London to San Diego?
A nonstop flight from London to San Diego takes about 11 h 5 min, for a straight-line distance of about 8,810 km.
Near San Diego
Other destinations close by.