Sunday, 1 August 2021 - Monthly Climate Summary for Western Australia - Product code IDCKGC11R0

Western Australia in July 2021: very warm days in the Kimberley; wet in the south-west

Mean maximum temperatures were above average for most of Western Australia except in the south-west. Mean minimum temperatures were above average across most of the state. For WA as a whole, it was the eighth-highest July mean maximum temperature on record, and the fourth-highest July mean minimum temperature on record. Rainfall was above average for much of the South West Land Division (SWLD) and adjacent southern Goldfields, while rainfall was close to average or below average for the reminder of the state.

Wet in the south-west WA

• July rainfall was 7% above 1961–90 average, and it was the wettest July since 2016 for Western Australia.
• For southwestern Western Australia (south-west of a line between Jurien Bay and Brember Bay), July rainfall was 55% above 1961–90 average, and the wettest July since 1996.
• For the SWLD (roughly south-west of a line between Geraldton and Esperance), July rainfall was 50% above 1961–90 average, and the wettest July since 1996.
• Many sites in the SWLD had their wettest July on record, or their wettest July in decades, including several sites with 50 to 140 years of record.
• A cut-off low pressure system and associated cloudband produced widespread moderate rainfall in a large area from southern Gascoyne to much of the SWLD on the 21st and 22nd; a number of sites in the Great Southern District had their highest July daily rainfall on record on the 21st.
• A pair of strong cold fronts produced widespread moderate rainfall to much of the SWLD on the 27th, and heavier falls to 60-80 mm were recorded along and just south of the Perth hills; several sites had their highest July daily rainfall on record.
• It was exceptionally wet in the Perth hills with a number of sites recorded July totals in excess of 400 mm; 459.2 mm at Bickley was the highest of the month in the state, and it was also its annual highest monthly rainfall in 53 years of record.
• Wagin (in the Great Southern District) recorded 148.3 mm in total, which was its fourth-wettest July on record, and the wettest July since 1958
• Katanning (south of Wagin) recorded 135.6 mm in total, which was town's equal third-wettest July on record, the wettest July for the town since 1958 with records commencing in 1891.
• Wandering (north-west of Wagin) recorded 227.4 mm in total, which was town's fourth-wettest July on record, the wettest July for the town since 1958 with records commencing in 1887.

Warmer daytime and night-time temperatures for most of WA

• The Western Australia mean temperature for July was 1.60 °C above 1961–90 average, which was the third-warmest July on record.
• Mean maximum temperatures were above average for most of the state away from the south-west where mean maxima were close to average.
• The mean maximum temperature was 1.67 °C above 1961–90 average, the equal eighth-highest July mean maximum temperatures on record for Western Australia.
• The mean minimum temperature was 1.52 °C above 1961–90 average, the fourth-highest July mean minimum temperatures on record, and highest since 1996 for Western Australia.
• Days were exceptionally warm in the north and east Kimberley in late July, resulting in a number of July highest daily temperature records, and warmest July days on record.
• A maximum temperature of 38.1 °C was recorded on the 24th at Kalumburu, and on the 29th and 30th at Wyndham Airport, which is the country's second-highest July temperatures on record, behind 38.3 °C at Kalumburu on 24 July 2016.
• Mean minimum temperatures were above average across almost the entire state, and it was particularly warm in the west; several sites in the SWLD had their warmest July nights on record, or warmest for at least 20 years.

Multiple severe weather events with damaging winds, heavy rainfall and flooding in the south-west of the state including Perth

• Frequent passage of a dozen or so cold fronts and a cut-off low during July resulted in multiple notable severe weather events of damaging winds, heavy rainfall, flash flooding reported in Perth and the south-west of the state.
• Damaging wind gusts in excess of 90 km/h were recorded in 13 of 31 days in the coastal locations of the south-west or in the Perth Hills. Cape Leeuwen recorded a destructive gust of 134 km/h on the 27th, which is its highest gust since 22 September 2013 (143 km/h).
• Heavy rainfall and strong winds caused flash flooding, damage in houses and properties across Perth and further south. There were close to 800 call outs to the DEFS for assistance for July.
• Water flooded the Ballagin Road in Piesseville, north of Wagin in the Great Southern District on the 28th, with the occupant of an abandoned vehicle was unaccountable.
• Over 20,000 properties with majority in Perth, lost power on the 26th and 27th.
• River levels in the Swan River and Avon River catchments peaked between 1–4 meters during July, which was their highest river level in winter since August 1996, although, the peak level at York (east of Perth) was the highest in any month since August 1998.

Extremes Maps Records Summaries Important notes the top

Extremes Maps Records Summaries Important notes the top

Maps
	Observed	Anomaly	Decile rank
Total rainfall
Mean daily maximum temperatures
Mean daily minimum temperatures

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* note: there are gaps in the historical record at this site, so it is possible a higher value has gone unreported

* note: there are gaps in the historical record at this site, so it is possible a higher value has gone unreported

Extremes Maps Records Summaries Important notes the top

Extremes Maps Records Summaries Important notes the top