The area's warm and humid climate is caused primarily by its low elevation and its position relatively close to the Tropic of Cancer, and much of its weather is affected by the movement of the Gulf Stream.

During the height of Orlando's very humid summer season, temperatures rarely fall below 70 °F (21 °C), and daytime highs average in the 90s (32-37 °C). Although the city rarely records temperatures over 100 °F (38 °C), extreme humidity often pushes the heat index to over 110 °F (43 °C). The city's highest recorded temperature is 102 °F (39 °C), set in 1998. During these months, strong afternoon thunderstorms occur almost daily.

These storms are caused by air masses from the Gulf of Mexico and the Atlantic Ocean colliding over Central Florida, and they often bring high wind, damaging hail, heavy rainfall (sometimes several inches per hour), and violent lightning. Orlando is sometimes referred to as the lightning capital of the world, but it is actually second to parts of Central Africa in its frequency of strikes. It does have more lightning than any other city in the United States. The humidity also prevents temperatures from varying much from day to day.

During the winter season, humidity is lower and temperatures are more moderate, and can fluctuate more readily. Average lows in January are around 50 °F (10 °C), and the highs average near 70 °F (21 °C). Temperatures rarely reach below 32 °F (0 °C), although the coldest temperature ever recorded was 16 °F (-9 °C) in 1985.

Because the winter season is dry and most freezing temperatures occur after cold fronts (and their accompanying precipitation) have passed, Orlando experiences no real snowfall. Although no measurable amount of snow has ever fallen (though areas just west recorded up to 2" in 1977), trace amounts were officially observed on December 23, 1989, and trace flurries of ocean effect snow were also reported in nearby coastal Brevard County on January 24, 2003. Another incident of snow flurries, mixed with rain, occurred on November 21, 2006. When flurries do occur, most are isolated incidents that are never officially recorded.

The average annual rainfall in Orlando is 50.1 in. (128 cm), most of it occurring in the period from June to September. The months of December through May are Orlando's driest season. During this period (especially in its later months), there is often a wildfire hazard. During some years, fires have been severe. In 1998, an El Niño condition caused an usually wet January and February, followed by drought throughout the spring and early summer, causing a record wildfire season that created Greater Orlando's first instances of unhealthy air quality alerts.

Orlando has a considerable hurricane risk, although it is not as high as it is in South Florida's urban corridor or other coastal regions. Since the city is located 40 miles (64 km) inland from the Atlantic and 60 miles (97 km) inland from the Gulf of Mexico, hurricanes usually weaken before arriving. Storm surges are not a concern since the region is 100 ft (30 m) above sea level. Despite its relatively safe location, the city does see strong hurricanes. During the notorious 2004 hurricane season, Orlando was hit by three hurricanes that caused significant damage, with Hurricane Charley the worst of these. The city also experienced widespread damage during Hurricane Donna in 1960.