This post checks RAW monthly Tmax data from Melbourne Regional Office over the period 1900 to 1920 against all other nearby stations that have useful data in this period.
In previous posts Melbourne has largely been a spectator in the detection and correction of non-climatic step changes in the Tmax data from coastal stations to the South. Those coastal stations have visually similar climate histories, tracking Melbourne (86071) quite closely, but with lower average temperatures. A regional climate history is beginning to take shape, but it is necessary to check it for consistency against all nearby stations (BoM ids in brackets): Brighton Middle (86161), Geelong SEC (87025), Queenscliff (87054) and Lorne Post Office (90054). Locations are shown in the following map:
The following figure shows anomalies of 12-month moving averages of monthly Tmax data from Melbourne and Queenscliff, the latter providing another example of a large step down in 1898. After the step there is a high level of consistency with Melbourne.
The following figure compares Melbourne with Brighton Middle, showing a high level of consistency, though the latter station may have a step down in its first few years.
Next up is Geelong SEC, which shows a step down of around 0.9C (annual average) in 1908 (that date again), closely consistent with Melbourne both before and after the step, apart from a possible inhomogeneity in 1915.
LORNE POST OFFICE
Last up is Lorne Post Office, with a very large step down in 1906. This data has many missing months, but is still useful for checking Melbourne in some periods.
Melbourne Regional Office RAW monthly Tmax data has no MAJOR non-climatic features during the period 1900 to 1920, a useful stepping stone on the path to a regional climate reconstruction to present times.