San Diego is famous for its mild, sunny climate year-round. Located along Southern California’s coast, the city enjoys warm temperatures, low humidity, and relatively little rainfall compared to much of the United States. Below is a month-by-month guide to San Diego’s weather to help you plan travel, outdoor activities, or relocation.
San Diego Weather by Month
San Diego Weather in January
- Average highs: mid-60s °F (around 18–20°C)
- Average lows: upper 40s to low 50s °F (9–11°C)
- Rainfall: One of the wetter months
January is cool and comfortable, especially by Southern California standards. Rain is possible, but sunny days are still common. Evenings can feel chilly near the coast.
San Diego Weather in January
- Average highs: mid-60s °F
- Average lows: low 50s °F
- Rainfall: Moderate, similar to January
February continues the mild winter pattern. Ocean temperatures remain cool, but hiking and sightseeing are pleasant thanks to mild daytime conditions.
San Diego Weather in March
- Average highs: upper 60s °F (around 20°C)
- Average lows: low to mid-50s °F
- Rainfall: Decreasing
Spring begins to arrive in March. Rain tapers off, wildflowers may bloom after wet winters, and temperatures slowly warm.
San Diego Weather in April
- Average highs: high 60s to low 70s °F (20–22°C)
- Average lows: mid-50s °F
- Rainfall: Low
April is sunny and comfortable, ideal for outdoor activities. Coastal breezes keep temperatures moderate.
San Diego Weather in May
- Average highs: low to mid-70s °F (22–24°C)
- Average lows: upper 50s to low 60s °F
- Rainfall: Very low
May often brings “May Gray,” when mornings can be cloudy along the coast. Skies usually clear by afternoon, making it a great month for travel.
San Diego Weather in June
- Average highs: low to mid-70s °F
- Average lows: low 60s °F
- Rainfall: Minimal
June is known for “June Gloom,” with marine-layer clouds in the morning. Inland areas tend to be sunnier and warmer than the coast.
San Diego Weather in July
- Average highs: mid to upper 70s °F (24–26°C)
- Average lows: mid-60s °F
- Rainfall: Very low
July is warm but rarely extreme. Coastal areas stay cooler, while inland neighborhoods can feel noticeably hotter.
San Diego Weather in August
- Average highs: upper 70s °F (25–27°C)
- Average lows: mid to upper 60s °F
- Rainfall: Low, with occasional humidity
August is typically the warmest month. Ocean temperatures peak, making it the best time for swimming and beach activities.
San Diego Weather in September
- Average highs: upper 70s to low 80s °F (26–28°C)
- Average lows: mid-60s °F
- Rainfall: Very low
September is often one of the best months in San Diego—warm, sunny, and less crowded as summer tourism winds down.
San Diego Weather in October
- Average highs: low to mid-70s °F (22–24°C)
- Average lows: low 60s °F
- Rainfall: Slight increase late in the month
October brings clear skies and comfortable temperatures. Santa Ana winds may occasionally cause warmer, drier conditions inland.
San Diego Weather in November
- Average highs: high 60s to low 70s °F (20–22°C)
- Average lows: mid-50s °F
- Rainfall: Increasing
November signals the transition to winter. Days remain pleasant, but evenings cool off, and rain becomes more likely.
San Diego Weather in December
- Average highs: mid-60s °F
- Average lows: upper 40s to low 50s °F
- Rainfall: One of the wetter months
December is mild compared to most of the U.S. While rain is more common, many days are still sunny and comfortable.
Summary Table: San Diego Weather by Month
| Month | Avg High (°F) | Avg Low (°F) | Rainfall |
|---|---|---|---|
| Jan | 65 | 49 | Moderate |
| Feb | 65 | 51 | Moderate |
| Mar | 67 | 53 | Low |
| Apr | 69 | 55 | Low |
| May | 72 | 59 | Very Low |
| Jun | 74 | 62 | Very Low |
| Jul | 77 | 65 | Very Low |
| Aug | 79 | 67 | Low |
| Sep | 80 | 66 | Very Low |
| Oct | 74 | 61 | Low |
| Nov | 69 | 56 | Moderate |
| Dec | 65 | 50 | Moderate |
Frequently Asked Questions (FAQs)
1. What is the best month to visit San Diego for good weather?
September is often considered the best month, offering warm temperatures, sunny skies, and fewer crowds compared to peak summer.
2. Does San Diego have a rainy season?
Yes. Most rainfall occurs between December and February, though rain is generally light and infrequent.
3. What is the coldest month in San Diego?
January is typically the coldest month, with average lows in the upper 40s to low 50s °F (9–11°C).
4. What is the hottest month in San Diego?
August is usually the warmest month, especially inland, with average highs in the upper 70s to low 80s °F (25–28°C).
5. Is San Diego humid?
San Diego has relatively low humidity year-round, though late summer can feel slightly more humid near the coast.
6. What are “May Gray” and “June Gloom”?
These terms describe coastal marine-layer clouds that cause overcast mornings in May and June, often clearing by afternoon.
7. Does it ever snow in San Diego?
Snow is extremely rare in the city itself. Nearby mountains may see snow during winter storms.
8. Is San Diego weather the same inland and along the coast?
No. Coastal areas are cooler and breezier, while inland neighborhoods are usually warmer, especially in summer.
9. Can you swim in the ocean year-round in San Diego?
Yes, but ocean temperatures are coolest in winter and warmest from July through September. Many swimmers use wetsuits in colder months.
10. Is San Diego a good place to live for year-round outdoor activities?
Absolutely. The mild climate supports outdoor activities like hiking, biking, surfing, and beachgoing throughout the year.
Final Thoughts
San Diego’s weather is consistently pleasant, with no true extremes. Whether you prefer mild winters, warm beach days, or sunny fall afternoons, there’s no bad time of year to enjoy the city.