Monday, 3 February 2020 - Monthly Climate Summary for Greater Sydney - Product code IDCKGC15L0

Greater Sydney in January 2020: record heat, severe storms, smoke and dust

Greater Sydney experienced a range of significant weather during January 2020, including extreme heat, severe thunderstorms and poor air quality from continuing bushfires nearby. Overall, mean minimum and maximum temperatures were warmer than average. Rainfall was generally below average, however, there were more rain days than usual.

Below average rainfall totals

• Rainfall was slightly below average across the region with most sites recording 50% to 80% of their average January rainfall totals; Camden, Campbelltown and Terrey Hills however, reported above average rainfall for the month
• A deep inland trough drew in humid air across the region, resulting in widespread shower and thunderstorm activity from the 16th to 18th, with lighter and more isolated falls persisting for a further few days; 65.4 mm was recorded at Cooranbong (Lake Macquarie AWS) in the north of the region on the 18th, the wettest day of the month
• Other rain days were generally the result of isolated thunderstorm activity, most notably on the 20th
• The rain fell over 15 days at Sydney (Observatory Hill), which is above the January average of 12 days
• Sydney Airport recorded 5.1 hours of bright sunshine per day, well below the average of 7.5 hours per day

Warm days and nights throughout

• Mean maximum temperature were mostly 1 °C to 2 °C above average across the region, with Mount Boyce and Katoomba in the Blue Mountains recording daytime temperatures 3.0 °C and 3.6 °C above the January average respectively
• The 4th saw exceptional heat and elevated fire danger across Greater Sydney, with dry and gusty hot northwest winds sweeping over the area; most sites reached the mid 40s on this day and many sites had their highest January temperature on record
• Penrith Lakes AWS recorded 48.9 °C on the 4th, which broke the record for the highest temperature ever recorded in the Sydney basin (exceeding the previous record of 47.8 °C recorded at Richmond RAAF in 1939)
• The heat and elevated fire danger returned on the 23rd, with many sites exceeding 40 °C, before a strong and gusty southerly change moved through the region bringing cooler conditions and isolated thunderstorm activity
• Sydney (Observatory Hill) recorded seven days of 30 °C or higher, which is double the average number of days for January
• Mean minimum temperatures were also above average in Greater Sydney, with most sites being 1 °C to 2 °C above average for the month
• Norah Head had its warmest January night (highest daily minimum temperature) on record on the 24th, and also its highest January mean daily minimum temperature on record

Sydney (Observatory Hill)

• Total rainfall for Sydney (Observatory Hill) was 71.4 mm, which is 71% of the long-term average of 101.2 mm
• The mean daily maximum temperature for Sydney (Observatory Hill) was 28.1 °C, which is 2.1 °C above the long-term average of 26.0 °C and the seventh-warmest on record for January
• The warmest day was 41.3 °C on the 23rd, and the coolest day was on the 17th when the temperature reached 22.1 °C
• The mean daily minimum temperature for Sydney (Observatory Hill) was 20.9 °C, which is 2.1 °C above the long-term average of 18.8 °C and the equal fourth-warmest on record for January
• The coldest morning was 17.4 °C on the 13th, and the warmest morning was on the 26th when the minimum temperature was 24.5 °C

Other phenomena

• Severe thunderstorms moved over Greater Sydney on the 20th, with widespread hail reported; several locations reported hail up to 4.5 cm, with up to 6 cm hail being reported in Sydney's southwest. Damaging winds in the Sutherland Shire resulted in trees downed and power outages. Two people were hospitalised due to being struck by lightning at Katoomba.
• Poor air quality was recorded on several days in Sydney due to nearby bushfire activity and dust; raised dust in the air resulted in brown dirty rain falling in Greater Sydney, with the worst of it falling on the 24th

Extremes Maps Records Summaries Daily observations Important notes the top

Extremes Maps Records Summaries Daily observations Important notes the top

Extremes Maps Records Summaries Daily observations Important notes the top

Extremes Maps Records Summaries Daily observations Important notes the top

Extremes Maps Records Summaries Daily observations Important notes the top