The climate varies with elevation.
At Katoomba, (1,010 m or 3,314 ft) the summer average maximum temperature is around 22 °C with a few days extending into the 30s (80s–90s °F) although it is quite common to see maximum temperatures stay in the teens when east coast troughs persist.
Night-time temperatures are usually in the teens but can drop to single figures at times.

During winter, the temperature is typically around 10 to 11 °C in the daytime with −1 °C or so on clear nights and 3 to 4 °C on cloudy nights.
Very occasionally it will get down to −3 °C or slightly lower but usually the coldest air drains into the valleys during calm, clear nights.
However, the passing of cold fronts can significantly lower the average temperature during the night and the day.
The Blue Mountains is not known for particularly cold mornings compared to other areas on the Central Tablelands, such as Oberon, Bathurst and Orange.
There are two to three snowfalls per year.

Annual rainfall is about 1,050 millimetres (41 in) in the Upper Blue Mountains with many misty days.
The climate varies with elevation. At Katoomba, (1,010 m or 3,314 ft) the summer average maximum temperature is around 22 °C with a few days extending into the 30s (80s–90s °F) although it is quite common to see maximum temperatures stay in the teens when east coast troughs persist. Night-time temperatures are usually in the teens but can drop to single figures at times.
During winter, the temperature is typically around 10 to 11 °C in the daytime with −1 °C or so on clear nights and 3 to 4 °C on cloudy nights. Very occasionally it will get down to −3 °C or slightly lower but usually the coldest air drains into the valleys during calm, clear nights. However, the passing of cold fronts can significantly lower the average temperature during the night and the day. The Blue Mountains is not known for particularly cold mornings compared to other areas on the Central Tablelands, such as Oberon, Bathurst and Orange. There are two to three snowfalls per year.
Annual rainfall is about 1,050 millimetres (41 in) in the Upper Blue Mountains with many misty days.
Blue Mountains (New South Wales)