| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 17.2° | 8.1° | 57.2mm | 6 | 79 |
| February | 16.9° | 8.4° | 59.7mm | 5.9 | 78 |
| March | 16.8° | 10° | 37.4mm | 5 | 80 |
| April | 17.5° | 11.4° | 20.6mm | 2.9 | 86 |
| May | 18.4° | 14° | 7.6mm | 1.9 | 91 |
| June | 19.2° | 15.8° | 1.2mm | 0.7 | 96 |
| July | 21.3° | 18° | 1.5mm | 0.5 | 99 |
| August | 22.2° | 18.3° | 2.5mm | 0.4 | 99 |
| September | 22.2° | 17.3° | 4.3mm | 0.9 | 98 |
| October | 21° | 14.3° | 16.5mm | 2.3 | 95 |
| November | 19.4° | 10.6° | 21.7mm | 3.3 | 91 |
| December | 17.4° | 8° | 42.4mm | 4.7 | 82 |
January in Oceanside averages a daily high of 17.2°C with nights around 8.1°C. Expect roughly 6 wet days totalling 57.2mm. Comfortable conditions for being outdoors all day.
February in Oceanside averages a daily high of 16.9°C with nights around 8.4°C. Expect roughly 5.9 wet days totalling 59.7mm. Comfortable conditions for being outdoors all day.
March in Oceanside averages a daily high of 16.8°C with nights around 10°C. Expect roughly 5 wet days totalling 37.4mm. Comfortable conditions for being outdoors all day.
April in Oceanside averages a daily high of 17.5°C with nights around 11.4°C. Rain is rare — about 2.9 wet days and 20.6mm across the month. Comfortable conditions for being outdoors all day.
May in Oceanside averages a daily high of 18.4°C with nights around 14°C. Rain is rare — about 1.9 wet days and 7.6mm across the month. Comfortable conditions for being outdoors all day.
June in Oceanside averages a daily high of 19.2°C with nights around 15.8°C. Rain is rare — about 0.7 wet days and 1.2mm across the month. Comfortable conditions for being outdoors all day.
July in Oceanside averages a daily high of 21.3°C with nights around 18°C. Rain is rare — about 0.5 wet days and 1.5mm across the month. Comfortable conditions for being outdoors all day.
August in Oceanside averages a daily high of 22.2°C with nights around 18.3°C. Rain is rare — about 0.4 wet days and 2.5mm across the month. Comfortable conditions for being outdoors all day.
September in Oceanside averages a daily high of 22.2°C with nights around 17.3°C. Rain is rare — about 0.9 wet days and 4.3mm across the month. Comfortable conditions for being outdoors all day.
October in Oceanside averages a daily high of 21°C with nights around 14.3°C. Rain is rare — about 2.3 wet days and 16.5mm across the month. Comfortable conditions for being outdoors all day.
November in Oceanside averages a daily high of 19.4°C with nights around 10.6°C. Expect roughly 3.3 wet days totalling 21.7mm. Comfortable conditions for being outdoors all day.
December in Oceanside averages a daily high of 17.4°C with nights around 8°C. Expect roughly 4.7 wet days totalling 42.4mm. 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. Oceanside peaks at 99.
Based on 30 years of records, May–November scores highest for comfort in Oceanside, balancing daytime temperature against rainfall.
August is the warmest, averaging a daily high of 22.2°C.
February is the wettest, averaging 59.7mm of rain across roughly 5.9 wet days.
March is the coolest month, with average daily highs around 16.8°C.