Significant Climate Anomalies and Events in 2004

PLEASE NOTE: The ranks and temperature anomalies in this report represent the values known at the time the report was issued. The actual ranks will change as subsequent years are added to the dataset. The anomalies themselves may change slightly as missing or erroneous data is resolved. Also, in 2009, NCDC switched to ERSST version 3b (from version 2) as a component of its global surface temperature dataset. Because the versions have slightly different methodologies, the calculated temperature anomalies will differ slightly. For more information about this switch please see the Global Surface Temperature Anomalies FAQ .

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Global Temperatures

Global temperatures in 2004 were 0.54°C (0.97°F) above the long-term (1880-2003) average**, ranking 2004 the fourth warmest year on record. The warmest year on record is 1998, having an anomaly of 0.63°C (1.13°F), followed by 2002 and 2003 both having an anomaly of 0.56°C (1.01°F). Land temperatures in 2004 were 0.83°C (1.50°F) above average, ranking fourth in the period of record while ocean temperatures were third warmest with 0.42°C (0.76°F) above the 1880-2003 mean. Global Blended Temperatures for 2004
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The map of temperature anomalies (above right) contains data from an in-situ and satellite blended data set of land and ocean temperatures. The period of record for this data set is 1988-2004, a relatively warm period compared to the base period used in the creation of the land only map of temperature anomalies. Some minor differences in the land surface anomalies between these two maps result from the differences in base periods and data that are used to construct the two maps.

The mean Northern Hemisphere temperature was near record levels in 2004 at 0.66°C (1.19°F), above the long-term average, 2nd warmest. The Southern Hemisphere temperature also reflected the globally warmer conditions, with a positive anomaly of 0.40°C (0.72°F) above the long-term average, 6th warmest .

**The 1880-2003 average combined land and ocean annual temperature is 13.9°C (56.9°F), the annually averaged land temperature for the same period is 8.6°C (47.4°F), and the long-term annually averaged sea surface temperature is 16.1°C (60.9°F).

Regional Temperatures

Global Temperature Anomalies
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Annual temperatures were above average across most land areas. The adjacent figure depicts warmer than average temperatures (for a 1961-1990 base period) that were widespread across much of the contiguous United States and Alaska, as well as most of Europe and Asia. Temperatures in these regions were 2-4°C (3.6-7.2°F) above the 1961-1990 average. This map was created using data from the Global Historical Climatology Network, a network of more than 7,000 land surface observing stations. The only widespread areas of negative anomalies were across western coastal areas of Australia, central Canada and north-central Siberia where temperatures were between 1 and 2°C (1.8-3.6°F) cooler than average.
Notable temperature extremes in 2004 included a severe heat wave that affected much of eastern Australia from February until the end of March. Many city and state temperature records were set as maximum temperatures reached 45°C (113°F). According to the Australian Bureau of Meteorology, the spatial and temporal extent of the heat wave was greater than that of any other February heat wave in the Australian meteorological record, and ranked amongst the top five Australian heat waves in any month, just short of the January 1939 event but comparable with those of January 2001, January 1982 and December 1972/January 1973. In Spain, during June and July, 73-year records were broken when maximum temperatures reached between 39-42°C (104-108°F). In Japan, a heat wave during mid-July produced a record temperature of 39°C (103°F) in Tokyo's financial district, the hottest temperature recorded since records began in 1923.

Early in the year, extreme cold temperatures as low as 0-5°C (32-41°F) in South Asia contributed to as many as 600 deaths from late December 2003 into January 2004. In July, cold temperatures were responsible for deaths of forty six children in Peru, along with more than 100,000 farm animals and 300,000 hectares (741,000 acres) of cropland destroyed. For more information on temperature extremes during 2004 see the annual report of Significant Events

Global Precipitation

Global Precipitation Anomalies
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Global precipitation was above the 1961-1990 average in 2004, the first time in 4 years. Regionally drier than average conditions were widespread across the western U.S. where the multi-year drought continued to ravage the region. India monsoon rainfall was 87 percent of normal, with the worst regional deficit being in northwest India with 22 percent less than average precipitation. The March-May rainy season was shorter and drier than normal across parts of the Greater Horn of Africa, resulting in a continuation of multi-season drought in this region. In Kenya only 50 percent of normal rainfall has fallen in the past two years. In Somalia, more than 600,000 people were directly affected by the current drought and in need of food aid.
There were also areas of above average precipitation in 2004. A winter storm brought heavy snowfall to much of the Mediterranean and Middle East regions in January. The storm blanketed areas with more than 61cm (2 feet) of snow causing the closing of local airports, an avalanche and three deaths. In Brazil, heavy rains that began in December and continued into February caused floods and mudslides, leaving tens of thousands of people homeless and killing at least 56 people. In April, a strong storm system brought 127-178mm (5-7 inches) of rain to the southwestern U.S. and adjacent areas in Mexico. Flash flooding of the Escondido River in Piedras Negras caused 36 deaths and damaged hundreds of homes. This event was characterized as some of the worst flooding on record along the U.S.-Mexico border. For more information about precipitation extremes during 2004, see the annual report of Significant Events.

Additional information on other notable weather events can be found in the Significant Events section of this report.

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NOAA's National Climatic Data Center is the world's largest active archive of weather data. The preliminary temperature and precipitation rankings are available from the center by calling: 828-271-4800.

NOAA works closely with the academic and science communities on climate-related research projects to increase the understanding of El Niño and improve forecasting techniques. NOAA's Climate Prediction Center monitors, analyzes and predicts climate events ranging from weeks to seasons for the nation. NOAA also operates the network of data buoys and satellites that provide vital information about the ocean waters, and initiates research projects to improve future climate forecasts.

Citing This Report

NOAA National Centers for Environmental Information, Monthly Global Climate Report for Annual 2004, published online January 2005, retrieved on February 21, 2024 from