Brisbane is situated in a humid subtropical climate zone (Köppen climate classification: Cfa), featuring hot, wet summers and mild, drier winters. The city boasts an annual mean minimum temperature of 16.6 °C (62 °F) and a mean maximum of 26.6 °C (80 °F), making it Australia's second-hottest capital city, trailing only Darwin. Seasonality is subtle in Brisbane, with average maximum temperatures consistently exceeding 26 °C (79 °F) from October to April.

The city's proximity to the Coral Sea and the influence of a warm ocean current contribute to relatively stable temperatures compared to other Australian capitals. While summers are long, hot, and humid, temperatures rarely exceed 35 °C (95 °F). During this season, about 80% of days see maximum temperatures ranging between 27 and 33 °C (81 to 91 °F). Winters, by contrast, are short and pleasant, with average maximums around 22 °C (72 °F), and temperatures dipping below 20 °C (68 °F) are uncommon.

The highest recorded temperature in Brisbane reached 43.2 °C (109.8 °F) on Australia Day in 1940, while the current station's highest temperature of 41.7 °C (107.1 °F) was recorded on February 22, 2004. However, temperatures above 38 °C (100 °F) are rare. On July 19, 2007, Brisbane experienced a historic moment when temperatures fell below freezing for the first time in recorded history, registering at −0.1 °C (31.8 °F) at the airport station. While the city station has never recorded temperatures below 2 °C (36 °F), areas further west, such as Ipswich, have seen temperatures drop as low as −5 °C (23 °F) with heavy frost.

Brisbane recorded its hottest winter day on August 24, 2009, when the mercury soared to 35.4 °C (95.7 °F). Despite this, average July temperatures hover around 22 °C (72 °F) under sunny skies and low humidity. Maximum temperatures below 18 °C (64 °F) are rare and typically occur during brief overcast periods and winter rains. The highest minimum temperature ever recorded was 28.0 °C (82.4 °F) on January 29, 1940, and again on January 21, 2017. Conversely, the lowest maximum temperature recorded was 10.2 °C (50.4 °F) on August 12, 1954.

Brisbane receives ample annual rainfall, with thunderstorms frequent from November to March. Severe storms can bring damaging hail, torrential rain, and strong winds. On average, Brisbane enjoys 124 clear days per year, with overcast conditions more prevalent in warmer months. The city’s wettest recorded day was January 21, 1887, when 465 millimeters (18.3 inches) of rain fell—marking the highest daily rainfall for any Australian capital. February 1893 holds the record for the wettest month, with 1,025.9 millimeters (40.39 inches) recorded, although more recent rainfall averages have been considerably lower.

Over the years, Brisbane has experienced significant flooding events, most notably in February 1893, January 1974 (partially due to Cyclone Wanda), January 2011 (influenced by Cyclone Tasha), and February 2022. The city lies within the southern reaches of the tropical cyclone risk zone; while full-strength tropical cyclones rarely make direct hits, ex-tropical cyclones pose a risk of destructive winds and heavy rainfall.

The average annual sea temperature ranges from 21.0 °C (69.8 °F) in July to 27.0 °C (80.6 °F) in February, further influencing Brisbane's climate and recreational activities throughout the year. As the city continues to grow, understanding its unique climate patterns remains essential for effective urban planning and disaster preparedness.