| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 21.2° | 6.2° | 44.1mm | 5.1 | 90 |
| February | 20.9° | 7.3° | 59.9mm | 5.4 | 89 |
| March | 23.3° | 8.4° | 31.4mm | 4.3 | 91 |
| April | 25.1° | 9.9° | 15.1mm | 2.2 | 96 |
| May | 27.7° | 13.2° | 5.6mm | 1.4 | 94 |
| June | 31° | 15.3° | 1.3mm | 0.2 | 84 |
| July | 35° | 18° | 2.7mm | 0.5 | 67 |
| August | 35.7° | 18.1° | 5.2mm | 0.4 | 64 |
| September | 33.8° | 16.9° | 3.6mm | 0.4 | 72 |
| October | 28.7° | 13° | 11.6mm | 1.1 | 91 |
| November | 24.3° | 8.4° | 17.6mm | 2.2 | 96 |
| December | 20.6° | 5.6° | 33.5mm | 3.7 | 93 |
January in Riverside averages a daily high of 21.2°C with nights around 6.2°C. Expect roughly 5.1 wet days totalling 44.1mm. Comfortable conditions for being outdoors all day.
February in Riverside averages a daily high of 20.9°C with nights around 7.3°C. Expect roughly 5.4 wet days totalling 59.9mm. Comfortable conditions for being outdoors all day.
March in Riverside averages a daily high of 23.3°C with nights around 8.4°C. Expect roughly 4.3 wet days totalling 31.4mm. Comfortable conditions for being outdoors all day.
April in Riverside averages a daily high of 25.1°C with nights around 9.9°C. Rain is rare — about 2.2 wet days and 15.1mm across the month. Comfortable conditions for being outdoors all day.
May in Riverside averages a daily high of 27.7°C with nights around 13.2°C. Rain is rare — about 1.4 wet days and 5.6mm across the month. Comfortable conditions for being outdoors all day.
June in Riverside averages a daily high of 31°C with nights around 15.3°C. Rain is rare — about 0.2 wet days and 1.3mm across the month. Comfortable conditions for being outdoors all day.
July in Riverside averages a daily high of 35°C with nights around 18°C. Rain is rare — about 0.5 wet days and 2.7mm across the month. Generally workable, with some weather to plan around.
August in Riverside averages a daily high of 35.7°C with nights around 18.1°C. Rain is rare — about 0.4 wet days and 5.2mm across the month. Generally workable, with some weather to plan around.
September in Riverside averages a daily high of 33.8°C with nights around 16.9°C. Rain is rare — about 0.4 wet days and 3.6mm across the month. Generally workable, with some weather to plan around.
October in Riverside averages a daily high of 28.7°C with nights around 13°C. Rain is rare — about 1.1 wet days and 11.6mm across the month. Comfortable conditions for being outdoors all day.
November in Riverside averages a daily high of 24.3°C with nights around 8.4°C. Rain is rare — about 2.2 wet days and 17.6mm across the month. Comfortable conditions for being outdoors all day.
December in Riverside averages a daily high of 20.6°C with nights around 5.6°C. Expect roughly 3.7 wet days totalling 33.5mm. 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. Riverside peaks at 96.
Based on 30 years of records, October–May scores highest for comfort in Riverside, balancing daytime temperature against rainfall.
August is the warmest, averaging a daily high of 35.7°C.
February is the wettest, averaging 59.9mm of rain across roughly 5.4 wet days.
December is the coolest month, with average daily highs around 20.6°C.