| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 4.7° | -5.3° | 92.4mm | 9.1 | 22 |
| February | 6.1° | -4.8° | 76.5mm | 7.8 | 30 |
| March | 10.7° | -0.7° | 101.1mm | 8.9 | 48 |
| April | 17.4° | 4.5° | 103.2mm | 11.1 | 69 |
| May | 22.7° | 10° | 110.7mm | 12.3 | 75 |
| June | 27.8° | 15.4° | 116.4mm | 11.1 | 75 |
| July | 30.7° | 18.5° | 121.6mm | 11.1 | 63 |
| August | 29.9° | 17.7° | 122.5mm | 10.4 | 68 |
| September | 25.9° | 13.4° | 119.3mm | 9.5 | 81 |
| October | 19.3° | 6.9° | 118.6mm | 11.3 | 75 |
| November | 12.7° | 1.1° | 85mm | 8.4 | 58 |
| December | 7.3° | -2.5° | 117.3mm | 9.6 | 33 |
January in Plainfield averages a daily high of 4.7°C with nights around -5.3°C. Expect roughly 9.1 wet days totalling 92.4mm. A hard month to visit for comfort alone.
February in Plainfield averages a daily high of 6.1°C with nights around -4.8°C. Expect roughly 7.8 wet days totalling 76.5mm. A hard month to visit for comfort alone.
March in Plainfield averages a daily high of 10.7°C with nights around -0.7°C. Expect roughly 8.9 wet days totalling 101.1mm. Demanding conditions — pack for it and plan indoor options.
April in Plainfield averages a daily high of 17.4°C with nights around 4.5°C. Expect roughly 11.1 wet days totalling 103.2mm. Generally workable, with some weather to plan around.
May in Plainfield averages a daily high of 22.7°C with nights around 10°C. Expect roughly 12.3 wet days totalling 110.7mm. Comfortable conditions for being outdoors all day.
June in Plainfield averages a daily high of 27.8°C with nights around 15.4°C. Expect roughly 11.1 wet days totalling 116.4mm. Comfortable conditions for being outdoors all day.
July in Plainfield averages a daily high of 30.7°C with nights around 18.5°C. Expect roughly 11.1 wet days totalling 121.6mm. Generally workable, with some weather to plan around.
August in Plainfield averages a daily high of 29.9°C with nights around 17.7°C. Expect roughly 10.4 wet days totalling 122.5mm. Generally workable, with some weather to plan around.
September in Plainfield averages a daily high of 25.9°C with nights around 13.4°C. Expect roughly 9.5 wet days totalling 119.3mm. Comfortable conditions for being outdoors all day.
October in Plainfield averages a daily high of 19.3°C with nights around 6.9°C. Expect roughly 11.3 wet days totalling 118.6mm. Comfortable conditions for being outdoors all day.
November in Plainfield averages a daily high of 12.7°C with nights around 1.1°C. Expect roughly 8.4 wet days totalling 85mm. Generally workable, with some weather to plan around.
December in Plainfield averages a daily high of 7.3°C with nights around -2.5°C. Expect roughly 9.6 wet days totalling 117.3mm. 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. Plainfield peaks at 81.
Based on 30 years of records, May–June scores highest for comfort in Plainfield, balancing daytime temperature against rainfall.
July is the warmest, averaging a daily high of 30.7°C.
August is the wettest, averaging 122.5mm of rain across roughly 10.4 wet days.
January is the coolest month, with average daily highs around 4.7°C.