

The following is a list of weather events that occurred in 2011. The year began with La Niña conditions. There were several natural disasters around the world from various types of weather, including blizzards, cold waves, droughts, heat waves, tornadoes, and tropical cyclones.
There was a strong La Niña event that began in 2010, and continued into 2012, which affected global weather conditions. The year was the second-wettest on record, only behind 2010, although some areas, such as the Horn of Africa, were drier than normal. The increased precipitation caused global sea level to drop by 5 mm (0.20 in). The global land temperature was the 8th warmest on record at the time, 0.8 °C (1.49 °F) above the 20th century average, and was also the warmest ever during a La Niña event.
| Rank | Event | Date(s) | Deaths (+Missing) | Refs |
|---|---|---|---|---|
| 1 | East Africa drought | July 2011 – 2012 | 50,000+ | |
| 2 | Tropical Storm Washi | December 13–19 | 1,257 | |
| 3 | 2011 Super Outbreak | April 25–28 | 324 | |
| 4 | Deep Depression BOB 04 | October 19–20 | 215 | |
| 5 | Tornado outbreak sequence of May 21–26, 2011 | May 21–26 | 178 | |
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The following listed different types of special weather conditions worldwide.
The deadliest weather event of the year was the East African drought, with the resulting food shortages and famine killing more than 50,000 people, many of them children. From March to August, a heat wave and drought persisted across much of the central United States, causing US$12 billion in damage and 95 deaths.

Throughout the year, there were 1,706 tornadoes in the United States, the third-highest on record. There were 553 deaths from tornadoes, making it the deadliest year for tornadoes in the country since modern records began in 1950. In late April, the U.S. experienced its most substantial tornado outbreak on record, with 360 confirmed tornadoes, including four EF5 tornadoes. The event resulted in 324 fatalities and US$10.2 billion in damage. A month later, an EF5 tornado hit Joplin, Missouri, killing 158 people, making it the deadliest tornado since 1950.

The Japan Meteorological Agency tracked 21 tropical storms in the western Pacific during the year, making it the fourth-quietest season since accurate records began in 1951. Of these, eight attained typhoon status, the strongest of which, Songda, attained 10 minute sustained winds of 195 km/h (120 mph) and a minimum pressure of 920 hectopascals (27 inHg). The first named storm, Aere, was named on May 7, while the final, Tropical Storm Washi, dissipated on December 19, days after causing damaging and deadly floods in the Philippines. Washi, known locally as Sendong, killed at least 1,257 people in the Philippines. The National Hurricane Center followed 19 tropical storms in the Atlantic Ocean, 10 becoming hurricanes, as well as 11 tropical storms in the eastern Pacific Ocean, 7 becoming hurricanes. In July, Hurricane Dora became the year's strongest tropical cyclone in the western hemisphere, with 1 minute sustained winds of 250 km/h (155 mph). Hurricane Irene was the year's costliest and deadliest for the Atlantic Ocean, killing 48 people and leaving US$13.5 billion in damage as it moved from the Caribbean up the East Coast of the United States. In October, the North Indian Ocean spawned its first cyclonic storm, Keila offshore Oman. The only other cyclonic storm, Thane, struck southeastern India in December. Outside of the official tropical cyclone basins, there was also an unusual system in the Mediterranean, Tropical Storm Rolf, which struck southern France.
Amid widespread drought conditions, there were widespread wildfires across the southern and southwestern United States from June to November, causing US$1.8 billion in damage and five deaths.
This is a timeline of deadly weather events during 2011.
| Global weather by year | ||
|---|---|---|
| Preceded by 2010 | Weather of 2011 | Succeeded by 2012 |