San Diego Weather by Month
San Diego has a mild Mediterranean climate with relatively warm temperatures throughout the year. Summers are warm and extremely dry, while most of the annual rainfall occurs from late fall through early spring. Ocean temperatures also vary seasonally, reaching their warmest levels in late summer.
San Diego Weather by Month
You can click the image below to view the full-size weather chart for San Diego.
January – Mild, Cool and Wet
Average high: 66°F (19°C)
Average low: 50°F (10°C)
Rainfall: 2.08 inches (52.8 mm)
Water temperature: 58°F
Daylight: 10.5 hours
January is one of the cooler and wetter months in San Diego. Average daytime temperatures reach around 66°F (19°C), while nighttime temperatures can fall to about 50°F (10°C).
Rainfall averages 2.08 inches (52.8 mm), making January one of the wetter months of the year. The Pacific Ocean is also relatively cool, with an average water temperature of about 58°F, which can feel chilly for swimming.
With mild air temperatures and moderate daylight, January is a good month for sightseeing, coastal walks, and exploring San Diego’s attractions.
Best for:
- Mild winter sightseeing
- Coastal walks
- City attractions
- Quieter beach visits
February – Mild and Occasionally Rainy
Average high: 66°F (19°C)
Average low: 52°F (11°C)
Rainfall: 2.06 inches (52.2 mm)
Water temperature: 57°F
Daylight: 11 hours
February remains mild in San Diego, with average highs around 66°F (19°C) and lows near 52°F (11°C).
Rainfall averages 2.06 inches (52.2 mm), so occasional wet weather is possible. The ocean reaches its coolest average temperature of the year at about 57°F, making swimming uncomfortable for many visitors without a wetsuit.
Daylight increases to around 11 hours, providing more time for sightseeing and outdoor activities.
Best for:
- Mild-weather sightseeing
- Coastal walks
- Exploring attractions
- Quieter visits
March – Mild Spring Weather
Average high: 66°F (19°C)
Average low: 54°F (12°C)
Rainfall: 1.83 inches (46.6 mm)
Water temperature: 58°F
Daylight: 12 hours
March brings mild spring weather to San Diego. Average daytime temperatures remain around 66°F (19°C), while nighttime temperatures rise to approximately 54°F (12°C).
Rainfall decreases to 1.83 inches (46.6 mm), although occasional showers can still occur. Ocean temperatures remain cool at about 58°F.
With around 12 hours of daylight, March offers increasingly favorable conditions for exploring parks, hiking trails, and the coastline.
Best for:
- Spring sightseeing
- Hiking
- Coastal walks
- Outdoor attractions
April – Warm, Dry and Comfortable
Average high: 68°F (20°C)
Average low: 57°F (14°C)
Rainfall: 0.71 inches (18 mm)
Water temperature: 60°F
Daylight: 13 hours
April marks a clear transition toward San Diego’s dry season. Average highs rise to around 68°F (20°C), while nighttime temperatures reach about 57°F (14°C).
Rainfall drops sharply to just 0.71 inches (18 mm), and daylight increases to around 13 hours. Ocean temperatures also begin to warm, averaging about 60°F.
The combination of mild temperatures, little rain, and longer days makes April a comfortable month for outdoor exploration.
Best for:
- Hiking and outdoor activities
- Beach walks
- Exploring parks
- Coastal sightseeing
May – Warm and Very Dry
Average high: 70°F (21°C)
Average low: 59°F (15°C)
Rainfall: 0.24 inches (6.2 mm)
Water temperature: 62°F
Daylight: 14 hours
May brings warmer weather and very little rainfall to San Diego. Average daytime temperatures reach around 70°F (21°C), while nighttime temperatures stay near 59°F (15°C).
Rainfall averages only 0.24 inches (6.2 mm), while daylight reaches approximately 14 hours. The Pacific Ocean continues to warm, reaching about 62°F on average.
The combination of warm air, dry weather, and long days makes May a good month for enjoying San Diego’s beaches and outdoor attractions.
Best for:
- Beach visits
- Hiking
- Outdoor sightseeing
- Coastal activities
June – Warm and Extremely Dry
Average high: 72°F (22°C)
Average low: 63°F (17°C)
Rainfall: 0.05 inches (1.3 mm)
Water temperature: 65°F
Daylight: 14 hours
June is warm, dry, and bright in San Diego. Average highs reach around 72°F (22°C), while nighttime temperatures remain mild at about 63°F (17°C).
Rainfall is extremely low at just 0.05 inches (1.3 mm), making June one of the driest months of the year. The ocean also becomes more comfortable, with an average water temperature of around 65°F.
With about 14 hours of daylight, June provides plenty of time for beaches, coastal walks, and outdoor activities.
Best for:
- Beach days
- Coastal sightseeing
- Hiking
- Outdoor recreation
July – Warm Summer Weather
Average high: 75°F (24°C)
Average low: 66°F (19°C)
Rainfall: 0.06 inches (1.5 mm)
Water temperature: 67°F
Daylight: 14 hours
July brings warm summer weather to San Diego. Average daytime temperatures reach about 75°F (24°C), while nighttime temperatures remain around 66°F (19°C).
Rainfall is almost nonexistent at just 0.06 inches (1.5 mm). Ocean temperatures rise to around 67°F, making the water more inviting for swimming and other water activities, although many people may still prefer a wetsuit.
With around 14 hours of daylight, July is well suited to spending long days outdoors.
Best for:
- Beach activities
- Swimming
- Coastal recreation
- Summer vacations
August – Warmest Water and Very Dry
Average high: 77°F (25°C)
Average low: 68°F (20°C)
Rainfall: 0.10 inches (2.5 mm)
Water temperature: 68°F
Daylight: 13.5 hours
August is one of the warmest months in San Diego, with average highs around 77°F (25°C) and lows near 68°F (20°C).
Rainfall remains extremely low at only 0.10 inches (2.5 mm). The Pacific Ocean reaches its warmest average temperature of the year at about 68°F, making August one of the more comfortable months for swimming and water activities.
With approximately 13.5 hours of daylight, visitors have plenty of time to enjoy beaches, parks, and coastal attractions.
Best for:
- Beach vacations
- Swimming
- Water activities
- Outdoor sightseeing
September – Warm and Dry
Average high: 77°F (25°C)
Average low: 66°F (19°C)
Rainfall: 0.19 inches (4.8 mm)
Water temperature: 66°F
Daylight: 12.5 hours
September continues San Diego’s warm and dry weather. Average highs remain around 77°F (25°C), while nighttime temperatures average about 66°F (19°C).
Rainfall is still very low at 0.19 inches (4.8 mm). The ocean remains relatively warm at around 66°F, while daylight lasts about 12.5 hours.
September is a good month for enjoying the coast, beaches, and outdoor attractions while temperatures remain comfortably warm.
Best for:
- Beach trips
- Swimming
- Coastal walks
- Outdoor sightseeing
October – Warm Days and Cooler Nights
Average high: 75°F (24°C)
Average low: 61°F (16°C)
Rainfall: 0.45 inches (11.5 mm)
Water temperature: 64°F
Daylight: 11.5 hours
October brings a gradual transition toward cooler autumn conditions. Average daytime temperatures remain warm at around 75°F (24°C), while nighttime temperatures fall to approximately 61°F (16°C).
Rainfall increases slightly to 0.45 inches (11.5 mm), but October remains relatively dry compared with winter. Ocean temperatures average around 64°F.
With 11.5 hours of daylight, there is still plenty of time for hiking, sightseeing, and coastal activities.
Best for:
- Autumn sightseeing
- Beach walks
- Hiking
- Exploring the city
November – Mild, Cooler and Increasingly Wet
Average high: 72°F (22°C)
Average low: 54°F (12°C)
Rainfall: 0.94 inches (23.9 mm)
Water temperature: 61°F
Daylight: 10.5 hours
November brings cooler temperatures and increasing rainfall to San Diego. Average highs reach around 72°F (22°C), while lows fall to about 54°F (12°C).
Rainfall rises to 0.94 inches (23.9 mm), while daylight decreases to approximately 10.5 hours. The ocean also cools to around 61°F.
Despite the seasonal change, San Diego remains mild enough for sightseeing, coastal walks, and many outdoor activities.
Best for:
- Mild-weather sightseeing
- Coastal walks
- City attractions
- Quieter visits
December – Mild Winter with More Rain
Average high: 66°F (19°C)
Average low: 50°F (10°C)
Rainfall: 1.55 inches (39.3 mm)
Water temperature: 59°F
Daylight: 10 hours
December returns to cooler winter conditions, with average highs around 66°F (19°C) and lows near 50°F (10°C).
Rainfall averages 1.55 inches (39.3 mm), making December one of the wetter months of the year. Ocean temperatures average about 59°F, while daylight is at its shortest point at around 10 hours.
Even in winter, San Diego remains relatively mild, making December suitable for sightseeing, coastal walks, and exploring the city’s attractions.
Best for:
- Mild winter travel
- City sightseeing
- Coastal walks
- Holiday attractions
San Diego Weather by Month
| Month | Avg High °F (°C) | Avg Low °F (°C) | Rainfall (inches) | Water Temperature | Daylight (hours) |
|---|---|---|---|---|---|
| January | 66°F (19°C) | 50°F (10°C) | 2.08 | 58°F | 10.5 |
| February | 66°F (19°C) | 52°F (11°C) | 2.06 | 57°F | 11 |
| March | 66°F (19°C) | 54°F (12°C) | 1.83 | 58°F | 12 |
| April | 68°F (20°C) | 57°F (14°C) | 0.71 | 60°F | 13 |
| May | 70°F (21°C) | 59°F (15°C) | 0.24 | 62°F | 14 |
| June | 72°F (22°C) | 63°F (17°C) | 0.05 | 65°F | 14 |
| July | 75°F (24°C) | 66°F (19°C) | 0.06 | 67°F | 14 |
| August | 77°F (25°C) | 68°F (20°C) | 0.10 | 68°F | 13.5 |
| September | 77°F (25°C) | 66°F (19°C) | 0.19 | 66°F | 12.5 |
| October | 75°F (24°C) | 61°F (16°C) | 0.45 | 64°F | 11.5 |
| November | 72°F (22°C) | 54°F (12°C) | 0.94 | 61°F | 10.5 |
| December | 66°F (19°C) | 50°F (10°C) | 1.55 | 59°F | 10 |
San Diego Weather FAQs
1. What is the weather like in San Diego?
San Diego has a mild Mediterranean climate with warm, dry summers and cooler, wetter winters. Temperatures generally remain comfortable throughout the year.
2. What is the hottest month in San Diego?
August and September are among the warmest months, with average highs of about 77°F (25°C).
3. What is the coldest month in San Diego?
January, February, and December are among the coolest months, with average highs around 66°F (19°C).
4. Does it snow in San Diego?
Snow is extremely rare in San Diego itself. Winter precipitation mainly falls as rain, while snow is more likely at higher elevations outside the city.
5. What is the rainiest month in San Diego?
January is the wettest month in the data, with about 2.08 inches (52.8 mm) of rainfall.
6. When is the dry season in San Diego?
The driest period generally runs from late spring through early fall. June, July, and August receive very little rainfall.
7. What month has the least rainfall in San Diego?
June has the lowest rainfall in the provided data, averaging just 0.05 inches (1.3 mm).
8. What is the average temperature in San Diego in January?
January has an average high of 66°F (19°C) and an average low of 50°F (10°C).
9. What is the weather like in San Diego in summer?
Summer is warm and very dry. Average highs range from about 72°F (22°C) in June to 77°F (25°C) in August and September.
10. Is San Diego warm in winter?
San Diego is relatively mild in winter. Average daytime temperatures are around 66°F (19°C), while nighttime temperatures generally fall to about 50–54°F (10–12°C).
11. What is the best month to visit San Diego for beach weather?
Late spring through early fall generally offers warm air temperatures, very little rain, and long daylight hours, making this period well suited to beach activities.
12. What is the ocean temperature in San Diego?
Average ocean temperatures range from about 57°F to 68°F throughout the year. The water is coolest in February and warmest around August.
13. What is the water temperature in San Diego in summer?
Average water temperatures are about 65°F in June, 67°F in July, 68°F in August, and 66°F in September.
14. Can you swim in San Diego in winter?
Swimming is possible, but ocean temperatures are relatively cool in winter, generally around 57–59°F. Many swimmers may prefer a wetsuit.
15. When is the warmest ocean water in San Diego?
August typically has the warmest average ocean temperature, at about 68°F.
16. How much daylight does San Diego get?
Daylight ranges from about 10 hours in December to around 14 hours in May, June, and July.
17. What month has the longest days in San Diego?
May, June, and July have the longest daylight periods in the provided data, at about 14 hours per day.
18. Is September a good month for outdoor activities in San Diego?
September has warm temperatures, very little rainfall, about 12.5 hours of daylight, and an average ocean temperature of around 66°F, making it suitable for many outdoor and coastal activities.
19. What is San Diego weather like in October?
October remains warm, with an average high of 75°F (24°C) and low of 61°F (16°C). Rainfall increases slightly to about 0.45 inches (11.5 mm).
20. What is the best time of year to visit San Diego?
San Diego can be visited throughout the year because of its mild climate. Late spring through early fall is generally characterized by warmer temperatures, very little rainfall, and longer daylight hours, while winter offers cooler temperatures and more rainfall.
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