| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 19.8° | 8.3° | 46mm | 5.4 | 89 |
| February | 19.5° | 9.1° | 51.7mm | 6.7 | 85 |
| March | 19.7° | 10.5° | 33.2mm | 4.8 | 89 |
| April | 20.4° | 12° | 16.5mm | 3.4 | 93 |
| May | 20.9° | 14.6° | 5.8mm | 1.6 | 97 |
| June | 21.9° | 16.2° | 0.7mm | 0.5 | 99 |
| July | 24.1° | 18.2° | 1.6mm | 0.3 | 99 |
| August | 25.4° | 18.8° | 1.6mm | 0.3 | 99 |
| September | 25.9° | 18.3° | 2.8mm | 0.7 | 99 |
| October | 24.1° | 14.7° | 10.8mm | 1.4 | 97 |
| November | 22° | 10.5° | 17.9mm | 2.8 | 94 |
| December | 19.5° | 8.2° | 37.5mm | 5 | 88 |
January in Chula Vista averages a daily high of 19.8°C with nights around 8.3°C. Expect roughly 5.4 wet days totalling 46mm. Comfortable conditions for being outdoors all day.
February in Chula Vista averages a daily high of 19.5°C with nights around 9.1°C. Expect roughly 6.7 wet days totalling 51.7mm. Comfortable conditions for being outdoors all day.
March in Chula Vista averages a daily high of 19.7°C with nights around 10.5°C. Expect roughly 4.8 wet days totalling 33.2mm. Comfortable conditions for being outdoors all day.
April in Chula Vista averages a daily high of 20.4°C with nights around 12°C. Expect roughly 3.4 wet days totalling 16.5mm. Comfortable conditions for being outdoors all day.
May in Chula Vista averages a daily high of 20.9°C with nights around 14.6°C. Rain is rare — about 1.6 wet days and 5.8mm across the month. Comfortable conditions for being outdoors all day.
June in Chula Vista averages a daily high of 21.9°C with nights around 16.2°C. Rain is rare — about 0.5 wet days and 0.7mm across the month. Comfortable conditions for being outdoors all day.
July in Chula Vista averages a daily high of 24.1°C with nights around 18.2°C. Rain is rare — about 0.3 wet days and 1.6mm across the month. Comfortable conditions for being outdoors all day.
August in Chula Vista averages a daily high of 25.4°C with nights around 18.8°C. Rain is rare — about 0.3 wet days and 1.6mm across the month. Comfortable conditions for being outdoors all day.
September in Chula Vista averages a daily high of 25.9°C with nights around 18.3°C. Rain is rare — about 0.7 wet days and 2.8mm across the month. Comfortable conditions for being outdoors all day.
October in Chula Vista averages a daily high of 24.1°C with nights around 14.7°C. Rain is rare — about 1.4 wet days and 10.8mm across the month. Comfortable conditions for being outdoors all day.
November in Chula Vista averages a daily high of 22°C with nights around 10.5°C. Rain is rare — about 2.8 wet days and 17.9mm across the month. Comfortable conditions for being outdoors all day.
December in Chula Vista averages a daily high of 19.5°C with nights around 8.2°C. Expect roughly 5 wet days totalling 37.5mm. 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. Chula Vista peaks at 99.
Based on 30 years of records, April–November scores highest for comfort in Chula Vista, balancing daytime temperature against rainfall.
September is the warmest, averaging a daily high of 25.9°C.
February is the wettest, averaging 51.7mm of rain across roughly 6.7 wet days.
February is the coolest month, with average daily highs around 19.5°C.