| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 8.7° | 1.5° | 173.2mm | 21.8 | 33 |
| February | 10.6° | 1.5° | 121.7mm | 18 | 39 |
| March | 13.1° | 2.5° | 125.4mm | 20.2 | 48 |
| April | 16° | 4° | 83.6mm | 17.3 | 57 |
| May | 20° | 6.9° | 58.1mm | 13.1 | 74 |
| June | 23.6° | 9.3° | 33.1mm | 8 | 84 |
| July | 28.9° | 11.3° | 6.6mm | 2.4 | 88 |
| August | 29° | 11.1° | 9.3mm | 3 | 86 |
| September | 25.3° | 9.1° | 42.3mm | 7.3 | 85 |
| October | 18.3° | 5.7° | 87.6mm | 15.2 | 65 |
| November | 12° | 3.3° | 169.2mm | 20.7 | 44 |
| December | 8.3° | 1.2° | 200.8mm | 22.1 | 31 |
January in Corvallis averages a daily high of 8.7°C with nights around 1.5°C. Expect roughly 21.8 wet days totalling 173.2mm. A hard month to visit for comfort alone.
February in Corvallis averages a daily high of 10.6°C with nights around 1.5°C. Expect roughly 18 wet days totalling 121.7mm. Demanding conditions — pack for it and plan indoor options.
March in Corvallis averages a daily high of 13.1°C with nights around 2.5°C. Expect roughly 20.2 wet days totalling 125.4mm. Demanding conditions — pack for it and plan indoor options.
April in Corvallis averages a daily high of 16°C with nights around 4°C. Expect roughly 17.3 wet days totalling 83.6mm. Generally workable, with some weather to plan around.
May in Corvallis averages a daily high of 20°C with nights around 6.9°C. Expect roughly 13.1 wet days totalling 58.1mm. Generally workable, with some weather to plan around.
June in Corvallis averages a daily high of 23.6°C with nights around 9.3°C. Expect roughly 8 wet days totalling 33.1mm. Comfortable conditions for being outdoors all day.
July in Corvallis averages a daily high of 28.9°C with nights around 11.3°C. Rain is rare — about 2.4 wet days and 6.6mm across the month. Comfortable conditions for being outdoors all day.
August in Corvallis averages a daily high of 29°C with nights around 11.1°C. Expect roughly 3 wet days totalling 9.3mm. Comfortable conditions for being outdoors all day.
September in Corvallis averages a daily high of 25.3°C with nights around 9.1°C. Expect roughly 7.3 wet days totalling 42.3mm. Comfortable conditions for being outdoors all day.
October in Corvallis averages a daily high of 18.3°C with nights around 5.7°C. Expect roughly 15.2 wet days totalling 87.6mm. Generally workable, with some weather to plan around.
November in Corvallis averages a daily high of 12°C with nights around 3.3°C. Expect roughly 20.7 wet days totalling 169.2mm. Demanding conditions — pack for it and plan indoor options.
December in Corvallis averages a daily high of 8.3°C with nights around 1.2°C. Expect roughly 22.1 wet days totalling 200.8mm. A hard month to visit for comfort alone.
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. Corvallis peaks at 88.
Based on 30 years of records, June–September scores highest for comfort in Corvallis, balancing daytime temperature against rainfall.
August is the warmest, averaging a daily high of 29°C.
December is the wettest, averaging 200.8mm of rain across roughly 22.1 wet days.
December is the coolest month, with average daily highs around 8.3°C.