| Month | High | Low | Rain | Wet days | Score |
|---|---|---|---|---|---|
| January | 23.9° | 13.5° | 165mm | 16.1 | 70 |
| February | 22.9° | 13.4° | 198.9mm | 14.6 | 71 |
| March | 20.9° | 11.9° | 205.1mm | 14.4 | 71 |
| April | 17.8° | 8.9° | 101.9mm | 10.6 | 72 |
| May | 14.1° | 6.2° | 90.1mm | 9 | 63 |
| June | 11° | 4° | 99mm | 10.8 | 50 |
| July | 10.4° | 2.9° | 75.7mm | 9.5 | 50 |
| August | 12.6° | 3.6° | 69.4mm | 8.7 | 59 |
| September | 16° | 6.1° | 64.7mm | 9.2 | 69 |
| October | 18.5° | 8.1° | 96.7mm | 10.7 | 74 |
| November | 20.8° | 10.2° | 141.9mm | 14.4 | 71 |
| December | 23° | 12° | 101.7mm | 13.8 | 72 |
January in Blue Mountains averages a daily high of 23.9°C with nights around 13.5°C. Expect roughly 16.1 wet days totalling 165mm. Generally workable, with some weather to plan around.
February in Blue Mountains averages a daily high of 22.9°C with nights around 13.4°C. Expect roughly 14.6 wet days totalling 198.9mm. Generally workable, with some weather to plan around.
March in Blue Mountains averages a daily high of 20.9°C with nights around 11.9°C. Expect roughly 14.4 wet days totalling 205.1mm. Generally workable, with some weather to plan around.
April in Blue Mountains averages a daily high of 17.8°C with nights around 8.9°C. Expect roughly 10.6 wet days totalling 101.9mm. Generally workable, with some weather to plan around.
May in Blue Mountains averages a daily high of 14.1°C with nights around 6.2°C. Expect roughly 9 wet days totalling 90.1mm. Generally workable, with some weather to plan around.
June in Blue Mountains averages a daily high of 11°C with nights around 4°C. Expect roughly 10.8 wet days totalling 99mm. Demanding conditions — pack for it and plan indoor options.
July in Blue Mountains averages a daily high of 10.4°C with nights around 2.9°C. Expect roughly 9.5 wet days totalling 75.7mm. Demanding conditions — pack for it and plan indoor options.
August in Blue Mountains averages a daily high of 12.6°C with nights around 3.6°C. Expect roughly 8.7 wet days totalling 69.4mm. Generally workable, with some weather to plan around.
September in Blue Mountains averages a daily high of 16°C with nights around 6.1°C. Expect roughly 9.2 wet days totalling 64.7mm. Generally workable, with some weather to plan around.
October in Blue Mountains averages a daily high of 18.5°C with nights around 8.1°C. Expect roughly 10.7 wet days totalling 96.7mm. Generally workable, with some weather to plan around.
November in Blue Mountains averages a daily high of 20.8°C with nights around 10.2°C. Expect roughly 14.4 wet days totalling 141.9mm. Generally workable, with some weather to plan around.
December in Blue Mountains averages a daily high of 23°C with nights around 12°C. Expect roughly 13.8 wet days totalling 101.7mm. Generally workable, with some weather to plan around.
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. Blue Mountains peaks at 74.
Based on 30 years of records, September–April scores highest for comfort in Blue Mountains, balancing daytime temperature against rainfall.
January is the warmest, averaging a daily high of 23.9°C.
March is the wettest, averaging 205.1mm of rain across roughly 14.4 wet days.
July is the coolest month, with average daily highs around 10.4°C.