Annual number of days above mean minima and maxima in Western Australia raw and ACORN database for:

Albany, Bridgetown, Broome, Cape Leeuwin, Carnarvon, Cunderdin, Dalwallinu, Eucla, Esperance, Forrest, Geraldton, Giles, Halls Creek, Kalgoorlie, Kalumburu, Katanning, Learmonth, Marble Bar, Meekatharra, Merredin, Perth, Port Hedland, Wandering

The charts below show there is often a notable increase in the annual number of days with average to above average minima or maxima after the introduction of a Small Stevenson Screen and/or an Automatic Weather Station. A 1998 study found slight differences in temperature recording between large and small Stevenson screens.

A 2015 Spanish study found: "Although the impact of these two different naturally ventilated wooden shelters was negligible in the differences encountered on daily minimum air temperatures (−0.11 °C on yearly average), it showed a noticeable overheating on daily maximum air temperatures (0.54 °C on yearly average) in the medium‐sized Stevenson screen."

There are also frequent shifts in average temperature immediately after 1972 Celsius metrication. The rapid increase in temperatures from 1972 is particularly apparent in charts with annual averages of all minimum and maximum daily temperatures recorded at the 23 stations from 1910 to 2011. This comparison excludes the WA ACORN stations of Wittenoom and Morawa because of their inconsistent daily recordings in both the ACORN and raw datasets (i.e. too many missing days to be accurate).

Among the 23 stations charted below, seven had Small Stevenson screens installed before 1992 and 16 from 1992 onward.

All Western Australia ACORN stations

Not all of the 23 stations charted above began recording in the same year, with later stations arguably distorting the averages - particularly Learmonth, a hot northerly station that began recording in 1976.

Below are the charted averages of the 13 ACORN stations in WA that began recording in 1910 and finished in 2011 - Albany, Bridgetown, Broome, Cape Leeuwin, Carnarvon, Esperance, Geraldton, Halls Creek, Kalgoorlie, Katanning, Marble Bar, Perth, Wandering.

Among the 13 stations charted below, four had Small Stevenson screens installed before 1992 and nine from 1992 onward.

Thirteen Western Australia ACORN stations with records starting 1910 and ending 2011

Albany

Bridgetown

Broome

Cape Leeuwin

Carnarvon

Cunderdin

Dalwallinu

Eucla

Esperance

Forrest

Geraldton

Giles

Halls Creek

Kalgoorlie

Kalumburu

Katanning

Learmonth

Marble Bar

Meekatharra

Merredin

Perth

Port Hedland

Wandering

This website produced by Scribeworks 2012