Newcastle humidity, heat and cold, month by month
Updated 3 October 2026 · 2 min read
Newcastle's afternoons are most humid in late summer (77 per cent in February at Nobbys) and driest in August (55 per cent). Summer days average 25 to 28°C; July nights fall to 8.5°C at Nobbys and 6.5°C at Williamtown.
Month by month
| Month | Nobbys max | Nobbys min | Williamtown max | Williamtown min | Afternoon humidity (Nobbys) |
|---|---|---|---|---|---|
| January | 25.6 | 19.3 | 28.3 | 18.2 | 74% |
| February | 25.4 | 19.4 | 27.7 | 18.2 | 77% |
| March | 24.8 | 18.4 | 26.4 | 16.5 | 73% |
| April | 22.8 | 15.4 | 23.8 | 13.3 | 68% |
| May | 20.1 | 12.0 | 20.4 | 10.1 | 66% |
| June | 17.5 | 9.8 | 17.7 | 8.0 | 64% |
| July | 16.8 | 8.5 | 17.2 | 6.5 | 59% |
| August | 18.1 | 9.3 | 18.8 | 7.0 | 55% |
| September | 20.3 | 11.6 | 21.6 | 9.2 | 59% |
| October | 22.2 | 14.1 | 23.9 | 12.1 | 65% |
| November | 23.6 | 16.2 | 25.7 | 14.5 | 71% |
| December | 24.9 | 18.1 | 27.5 | 16.7 | 72% |
Temperatures in °C: Bureau of Meteorology climate statistics, Newcastle Nobbys Signal Station and Williamtown RAAF, read 1 October 2026. Humidity: Bureau of Meteorology 1991 to 2020 normals for Nobbys, as tabled on Wikipedia.
What it means for your air-con
- January to March: warm and humid. Cool mode on hot days, dry mode on sticky overcast ones.
- June to August: cool nights, colder away from the coast. Heat mode on a reverse-cycle split is the usual answer.
- Spring and autumn: often mild enough for the fan alone.
Common questions
Is Newcastle humid?
In late summer, yes: afternoon humidity at Nobbys averages 74 to 77 per cent from January to March, dropping to about 55 per cent in August.
How cold does Newcastle get?
July nights average 8.5°C at Nobbys and 6.5°C at Williamtown.
Sources
- Wikipedia, Newcastle, New South Wales (Nobbys climate table: Bureau of Meteorology 1991-2020 normals, humidity)
- Bureau of Meteorology, Climate statistics for Australian locations (Nobbys 061055 and Williamtown RAAF 061078, read 1 October 2026)
Checked 3 October 2026. Prices are published ranges, not quotes; rebates change, so confirm with the installer and the NSW Government.