| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 20.3° | 3.6° | 16.9mm | 3.7 | 93 |
| February | 22.6° | 5.1° | 23mm | 3.6 | 93 |
| March | 26.2° | 7.9° | 17.6mm | 2.8 | 94 |
| April | 31.4° | 11° | 5.1mm | 1.1 | 80 |
| May | 36.7° | 16.2° | 3.1mm | 0.7 | 60 |
| June | 40.9° | 20.8° | 2.5mm | 0.8 | 43 |
| July | 42.1° | 25.7° | 24.7mm | 3.6 | 33 |
| August | 40.9° | 25.2° | 36.7mm | 4.9 | 35 |
| September | 38.6° | 21.4° | 11.7mm | 2.4 | 49 |
| October | 33.1° | 13.9° | 4.8mm | 1.5 | 73 |
| November | 25.6° | 7.2° | 9.8mm | 1.6 | 97 |
| December | 20° | 3.3° | 20.3mm | 3.6 | 93 |
January in Casa Grande averages a daily high of 20.3°C with nights around 3.6°C. Expect roughly 3.7 wet days totalling 16.9mm. Comfortable conditions for being outdoors all day.
February in Casa Grande averages a daily high of 22.6°C with nights around 5.1°C. Expect roughly 3.6 wet days totalling 23mm. Comfortable conditions for being outdoors all day.
March in Casa Grande averages a daily high of 26.2°C with nights around 7.9°C. Rain is rare — about 2.8 wet days and 17.6mm across the month. Comfortable conditions for being outdoors all day.
April in Casa Grande averages a daily high of 31.4°C with nights around 11°C. Rain is rare — about 1.1 wet days and 5.1mm across the month. Comfortable conditions for being outdoors all day.
May in Casa Grande averages a daily high of 36.7°C with nights around 16.2°C. Rain is rare — about 0.7 wet days and 3.1mm across the month. Generally workable, with some weather to plan around.
June in Casa Grande averages a daily high of 40.9°C with nights around 20.8°C. Rain is rare — about 0.8 wet days and 2.5mm across the month. Demanding conditions — pack for it and plan indoor options.
July in Casa Grande averages a daily high of 42.1°C with nights around 25.7°C. Expect roughly 3.6 wet days totalling 24.7mm. A hard month to visit for comfort alone.
August in Casa Grande averages a daily high of 40.9°C with nights around 25.2°C. Expect roughly 4.9 wet days totalling 36.7mm. Demanding conditions — pack for it and plan indoor options.
September in Casa Grande averages a daily high of 38.6°C with nights around 21.4°C. Rain is rare — about 2.4 wet days and 11.7mm across the month. Demanding conditions — pack for it and plan indoor options.
October in Casa Grande averages a daily high of 33.1°C with nights around 13.9°C. Rain is rare — about 1.5 wet days and 4.8mm across the month. Generally workable, with some weather to plan around.
November in Casa Grande averages a daily high of 25.6°C with nights around 7.2°C. Rain is rare — about 1.6 wet days and 9.8mm across the month. Comfortable conditions for being outdoors all day.
December in Casa Grande averages a daily high of 20°C with nights around 3.3°C. Expect roughly 3.6 wet days totalling 20.3mm. 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. Casa Grande peaks at 97.
Based on 30 years of records, November–March scores highest for comfort in Casa Grande, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 42.1°C.
August is the wettest, averaging 36.7mm of rain across roughly 4.9 wet days.
December is the coolest month, with average daily highs around 20°C.