| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 18.8° | 9.9° | 48.7mm | 6.6 | 83 |
| February | 18.8° | 10.6° | 50.7mm | 6.7 | 83 |
| March | 19.2° | 12.2° | 31.5mm | 6.2 | 85 |
| April | 20.1° | 13.5° | 15.8mm | 3.9 | 92 |
| May | 20.5° | 15.5° | 7.1mm | 2.2 | 96 |
| June | 21.7° | 16.9° | 0.8mm | 0.7 | 99 |
| July | 23.9° | 18.9° | 1.9mm | 0.5 | 99 |
| August | 25.1° | 19.7° | 1.9mm | 0.3 | 99 |
| September | 25° | 19° | 3.8mm | 1.1 | 98 |
| October | 23.4° | 16.2° | 12.7mm | 2.4 | 95 |
| November | 21.3° | 12.5° | 20.4mm | 3.7 | 93 |
| December | 18.7° | 9.8° | 41.6mm | 5.6 | 85 |
January in San Diego averages a daily high of 18.8°C with nights around 9.9°C. Expect roughly 6.6 wet days totalling 48.7mm. Comfortable conditions for being outdoors all day.
February in San Diego averages a daily high of 18.8°C with nights around 10.6°C. Expect roughly 6.7 wet days totalling 50.7mm. Comfortable conditions for being outdoors all day.
March in San Diego averages a daily high of 19.2°C with nights around 12.2°C. Expect roughly 6.2 wet days totalling 31.5mm. Comfortable conditions for being outdoors all day.
April in San Diego averages a daily high of 20.1°C with nights around 13.5°C. Expect roughly 3.9 wet days totalling 15.8mm. Comfortable conditions for being outdoors all day.
May in San Diego averages a daily high of 20.5°C with nights around 15.5°C. Rain is rare — about 2.2 wet days and 7.1mm across the month. Comfortable conditions for being outdoors all day.
June in San Diego averages a daily high of 21.7°C with nights around 16.9°C. Rain is rare — about 0.7 wet days and 0.8mm across the month. Comfortable conditions for being outdoors all day.
July in San Diego averages a daily high of 23.9°C with nights around 18.9°C. Rain is rare — about 0.5 wet days and 1.9mm across the month. Comfortable conditions for being outdoors all day.
August in San Diego averages a daily high of 25.1°C with nights around 19.7°C. Rain is rare — about 0.3 wet days and 1.9mm across the month. Comfortable conditions for being outdoors all day.
September in San Diego averages a daily high of 25°C with nights around 19°C. Rain is rare — about 1.1 wet days and 3.8mm across the month. Comfortable conditions for being outdoors all day.
October in San Diego averages a daily high of 23.4°C with nights around 16.2°C. Rain is rare — about 2.4 wet days and 12.7mm across the month. Comfortable conditions for being outdoors all day.
November in San Diego averages a daily high of 21.3°C with nights around 12.5°C. Expect roughly 3.7 wet days totalling 20.4mm. Comfortable conditions for being outdoors all day.
December in San Diego averages a daily high of 18.7°C with nights around 9.8°C. Expect roughly 5.6 wet days totalling 41.6mm. Comfortable conditions for being outdoors all day.
Each month scores out of 100. It starts at 100 and loses points for daytime highs outside a 20–27°C band, for wet days, and for nights below 2°C. Nothing else is weighted in — no crowd data, no prices, no opinion. San Diego peaks at 99.
Based on 30 years of records, April–November scores highest for comfort in San Diego, balancing daytime temperature against rainfall.
August is the warmest, averaging a daily high of 25.1°C.
February is the wettest, averaging 50.7mm of rain across roughly 6.7 wet days.
December is the coolest month, with average daily highs around 18.7°C.