Monday, 2 February 2015 - Monthly Climate Summary for Western Australia - Product code IDCKGC11R0

Western Australia in January 2015: Hot in the west, wet in the Kimberley

Mean maximum temperatures were above to very much above average across much of western and central WA in January, and a few sites in the South West and Great Southern registered record high mean maxima in January, whilst much of the Kimberley and Northern Interior, and a small area near the west Pilbara coast recorded below average day-time temperatures. Averaged across the State, the mean maximum temperature was 0.65 °C above the long-term average. Averaged across the Lower Southwest (southwest of a line from Jurien Bay to Bremer Bay), the January mean maximum for the region was 1.43 °C above the long-term average, and the seventh-highest since comparable records commenced in 1910.

A large pool of hot air stagnated over northwest WA during the second half of the month and resulted in daily maxima persistently in the mid- to high-forties. Several January temperature records were broken at sites in the northern Central West, Gascoyne and Pilbara districts as a result. Carnarvon Airport recorded a daily maximum temperature of 47.8 °C on the 20th, which is the highest temperature in January at Carnarvon Airport in 69 years of record, and also the equal highest temperature for any month, equal with 47.8 °C on 6 March 2007. A daily maximum temperature of 49.0 °C at Marble Bar on the 23rd was its third highest temperature since records began in 1901, only behind 49.2 °C recorded on both 11 January 1905 and 3 January 1922.

Mean minimum temperatures were above to very much above average in a large area covering northwest, central, and southern WA, whilst areas in the west and southeast Kimberley, as well as the eastern Northern Interior saw below average mean minimum temperatures. Averaged across the State, the mean minimum temperature was 0.62 ° C above the long-term average, whilst for the Lower Southwest the mean minimum was near average at 0.10 °C above the mean.

Rainfall in January 2015 was below to very much below average in patchy areas of the Pilbara and Gascoyne, and in much of the eastern and coastal SWLD, and Goldfields. Sites in the Southwest, South Coastal, Goldfields, east Pilbara and west Kimberley recorded their driest January in at least 20 years, whilst Walpole in the South West recorded its driest January in 64 years of record. Areas of above average rainfall were reported across large parts of the Kimberley and Northern Interior, and Curtin Aerodrome in the west Kimberley recorded its wettest January in its 21 year recording history. Averaged across the state as a whole, January 2015 rainfall was near average, whilst for the SWLD, rainfall in January 2015 was below average, and the driest for five years, since 2010. The Lower Southwest also recorded below average rainfall for January.

A significant tropical low developed near the north Kimberley on 2 January and remained over the Kimberley for the next week, first tracking southwest then south before turning eastward and moving through the east Kimberley into the Northern Territory on the 10th. Numerous sites in the Kimberley received very heavy rainfall during the event with daily totals commonly between 80 mm to 200 mm, resulting in some minor flooding on the King, Dunham and Fitzroy Rivers. Four sites in the Kimberley recorded their wettest January day on record. Cape Leveque recorded 400.0 mm on the 8th, from a rain gauge that had overflowed so the actual daily total was almost certainly higher, which was its wettest day for any month in 94 years of recording, and was WA's 10th highest January daily fall on record. Another tropical low tracked westward across the Kimberley from the 17th to 19th before moving off the west Kimberley coast. Warmun in the east Kimberley recorded 190.0 mm on the 19th, its highest daily fall in 108 years of recording, and significant stream rises with areas of flooding occurred in parts of the east and west Kimberley.

A deep trough near the west coast and across northern WA on 29 January triggered widespread thunderstorms in the western SWLD, Gascoyne and across the north. Hail up to 3 cm in diameter was reported in Collie in the South West. Moderate to heavy daily totals were recorded in the Kimberley, though rainfall was generally light in the Gascoyne and the southwest of the state. The event brought an end to a dry spell of sixty days or more for many sites around Perth and near the west coast, with the first rainfall recorded since late November 2014.

• Tropical lows brought heavy rainfall to the Kimberley from the 2nd to the 10th, and 17th to 19th
• Third-highest all-time temperature on record at Marble Bar on the 23rd (49.0 °C)
• Equal highest temperature on record at Carnarvon Airport on the 20th (47.8 °C)
• WA's tenth-highest January daily rainfall at Cape Leveque on the 8th (400.0 mm)
• Severe thunderstorms in the Gascoyne and the western SWLD on the 29th

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 lower 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.

* 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