The following is a list of weather events that occurred on Earth in the year 2023. The year saw a transition from La Niña to El Niño, with record high global average surface temperatures. There were several natural disasters around the world from various types of weather, including blizzards, cold waves, droughts, heat waves, wildfires, floods, tornadoes, and tropical cyclones. The deadliest weather event of the year was Storm Daniel, which caused catastrophic dam failures in Libya which lead to the deaths of over 5,900 people. The costliest weather event of the year was Typhoon Doksuri, which caused $28.5 billion in damages in China, the Philippines and Taiwan, becoming the costliest tropical cyclone outside of the North Atlantic basin. Another significant weather event was Cyclone Freddy, which became the longest lasting tropical cyclone on record, beating the previous mark of Hurricane John in 1994. The storm caused 1,434 fatalities, with most of the deaths coming from Malawi.

This is a list of weather events considered to be the most significant during 2023, in which reliable sources, surveys or academic assessments consider criteria such as, but not limited to: how impactful the event was, how deadly the event was, the impact on science, or other specific criteria. These events may be referred to as most important, most iconic, most significant, or the worst—but they are all considered key events in meteorology during the year.

The following listed different types of special weather conditions worldwide.

In January, a cold snap in Afghanistan killed at least 166 people and more than 80,000 livestock. A national low temperature was set in Mohe City, China at −53.0 °C (−63.4 °F), on January 23. Two days later, snow fell in Algeria for the first time in ten years. In late January, an ice storm impacted the southern portion of the Great Plains, leading to closures on interstates 10, 30, 35W, and 40 after numerous car accidents being reported. 0.8 in (2.0 cm) of freezing rain fell near Llano, Texas, while 0.62 in (1.6 cm) of freezing rain fell west of Leander, Texas. Dallas, Texas set a daily snowfall record on January 31, at 1.3 in (3.3 cm). In early February, extremely cold temperatures made it into the Northeast, following an arctic front moving in by February 2. The front brought dangerously low wind chills to much of the region, with snow showers and snow squalls being reported. By February 3-4, temperature readings went down to the single digits above zero, with the lowest being −10 °F (−23 °C) to −20 °F (−29 °C). On February 4, Albany, New York saw a record low −13 °F (−25 °C), while a record low of −24 °F (−31 °C) was set at Glens Falls, New York. Also on February 4, Boston experienced a temperature of −10 °F (−23 °C), smashing the February 4 record of −2 °F (−19 °C) set in 1886. Portland, Maine had a record-cold wind chill of −45 °F (−43 °C). On Mount Washington's summit in New Hampshire, the wind chill hit −108 °F (−78 °C), the coldest ever recorded in the United States, with an air temperature of −46 °F (−43 °C) combined with wind speeds of 97 mph (156 km/h). In early March, a massive snowstorm in Arizona led to many pileups, with interstates 17, 40, and U.S. 93 closing down. Between 20 in (51 cm) and 30 in (76 cm) of snow fell in Arizona. The storm later moved to the Northeast, with snow emergencies being issued in the Albany metropolitan area and near Pittsfield, Massachusetts. 7.8 in (20 cm) of snow fell in Albany as a result of the winter storm. Later in March, a nor'easter hit New England between March 12–15, with 270,000 individuals losing power, low visibility leading to over 200 car crashes, and a temporary shutdown of Interstate 93 in New Hampshire. 32.3 in (82 cm) of snow fell in Hunter, New York, with the highest total recorded at 42.1 in (107 cm) near Readsboro, Vermont. In early April, a massive blizzard hit the Great Plains, with blizzard warnings stretching 800 mi (1,300 km), from Wyoming to Minnesota. Casper, Wyoming set a record of a one-day and two-day record for snowfall, at 26.7 in (68 cm) and 37.4 in (95 cm), with Atlantic City recording 48.8 inches (124 cm) of snow. Kenora, Ontario saw 27.2 cm (10.7 in) of snow, setting the snowfall record for April 5. Salt Lake City saw a record cold high, at only 33 °F (1 °C). Between May 1–2, Marquette, Michigan received 26.2 in (67 cm) of snow, with 19.8 in (50 cm) falling on May 1, which is the greatest calendar snowfall for the month of May for Michigan. In addition, a snow depth of 20 in (51 cm) was recorded on the morning of May 2, shattering records for snow depth in the month of May.

Starting in April 2023, a record-breaking heat wave in Asia has affected multiple countries, including India, China, Laos and Thailand. In the Western Mediterranean region, starting in Northern Africa, there was a three-day heatwave from April 26 to 28. The temperature reached up to 40 °C (104 °F) in parts of Morocco and Algeria. On April 27, at Córdoba Airport in Spain, the temperature reached 38.8 °C (101.8 °F), breaking the previous April record of 38.6 °C (101.5 °F) set in Elche. Additionally, this marked the hottest temperature recorded in all of Europe in the month of April. Other parts of Spain had very high temperatures, with Mora reaching 36.9 °C (98.4 °F).

An early-season tornado outbreak in the Southern United States was responsible for eight deaths and 53 injuries. On January 24, an EF3 tornado struck Deer Park, Texas, causing a tornado emergency. A storm complex in late February caused several tornadoes including a tornado that hit Cheyenne, Oklahoma, that killed one. A rare tornado near Taif, Saudi Arabia killed one person and injured one more. Two separate tornado outbreaks between March 24–March 27 and March 31–April 1 caused 58 deaths and two EF4 tornadoes in the U.S.

The first named tropical cyclone of the year was Cyclone Hale, which caused minimal damage and one death in New Zealand as an extratropical cyclone. Later in January, Cyclone Cheneso killed at least 33 people in Madagascar and left 20 missing. In addition, it damaged over 13,000 houses and 18 medical centers. In February, Cyclone Freddy formed on February 4 and lasted until March 14, making it the longest lived tropical cyclone on record, surpassing Hurricane John of 1994, tracking across the entire Indian Ocean, the first to do so since Hudah and Leon-Eline in 2000. In addition, Freddy also recorded the highest accumulated cyclone energy of any tropical cyclone worldwide, at 87.01, surpassing the previous record of 85.26 by Hurricane Ioke in 2006. Freddy killed at least 1,434 people, and left 19 missing. In May, Cyclone Mocha formed and made landfall in Myanmar, killing 438 people and more than 101 missing. In June, Cyclone Biparjoy formed over the Arabian Sea and intensified into an extremely severe tropical cyclone, and made landfall in India, leaving at least 12 people dead.

Cyclone Helios which formed in early February brought recorded rain and humidity to Malta from 80 years. Luqa recorded rain with a total of 140.4 millimeters. meteo.it defined it as a Mediterranean tropical-like cyclone as it dissipated on February 11. Storm Otto, also known as Storm Ulf, brought high winds to the United Kingdom, Norway, and Germany. The highest wind gust was recorded in Cairngorms, UK, at 193 km/h (120 mph).