Monthly Climate Reports

Global Climate ReportMarch 2015

March 2015 Selected Climate
Anomalies and Events Map

Introduction

Temperature anomalies and percentiles are shown on the gridded maps below. The anomaly map on the left is a product of a merged land surface temperature (Global Historical Climatology Network, GHCN) and sea surface temperature (ERSST.v3b) anomaly analysis developed by Smith et al. (2008). Temperature anomalies for land and ocean are analyzed separately and then merged to form the global analysis. For more information, please visit NCDC's Global Surface Temperature Anomalies page. The percentile map on the right provides additional information by placing the temperature anomaly observed for a specific place and time period into historical perspective, showing how the most current month, season or year compares with the past.

The most current data may be accessed via the Global Surface Temperature Anomalies page.

Temperatures

In the atmosphere, 500-millibar height pressure anomalies correlate well with temperatures at the Earth's surface. The average position of the upper-level ridges of high pressure and troughs of low pressure—depicted by positive and negative 500-millibar height anomalies on the March 2015 height and anomaly map March 2015 and January - March 2015 height and anomaly map January–March 2015 maps—is generally reflected by areas of positive and negative temperature anomalies at the surface, respectively.

March

March 2015 Blended Land and Sea Surface
Temperature Anomalies in degrees Celsius

March Blended Land and Sea Surface Temperature Percentiles

March 2015 Blended Land and Sea Surface
Temperature Percentiles

The average temperature across global land and ocean surface temperatures combined for March 2015 was 0.85°C (1.53°F) higher than the 20^th century average of 12.7°C (54.9°F). This marks the highest March temperature in the 136-year period of record, surpassing the previous record of 2010 by 0.05°C (0.09°F). The Northern Hemisphere had its second highest March temperature on record, behind only 2008, while the Southern hemisphere tied with 2002 for third highest.

The March 2015 global temperature was the third highest monthly departure from average on record for any month, just 0.01°C (0.02°F) lower than the monthly anomalies for February 1998 and January 2007. This also replaces February 2015 (+0.84°C / +1.51°F) as the third highest departure from average among all months, moving that month to fourth highest. Seven of the past eleven months (May, June, August, September, October, and December 2014, along with March 2015) have tied or set new record high monthly temperatures.

The average March temperature over land surfaces across the globe tied with 1990 as the second highest for March on record, at 1.59°C (2.86°F) above the 20^th century average. The warmth was spread fairly evenly across the hemispheres, as the Northern and Southern Hemisphere each observed their third highest March land surface temperatures on record. Most land areas were warmer to much warmer than average, as shown by the Temperature Percentiles map above, with record warmth in parts of the western United States and Canada, various regions in eastern Africa, parts of Scandinavia and northwestern Russia, part of south central China, and an area of northeastern Australia. Central India, southeastern Mauritania, central Mexico, and eastern Canada were cooler than average. Part of northeastern Canada was much cooler than average, with the region observing temperatures at least 3°C (5°F) below average. On the other side of the continent, most of central to western North America had temperatures at least 3°C higher than the 20^th century average. Temperatures were also at least 3°C above average across most of Eurasia, with the exception of Far East Russia south of the East Siberian Sea, which was cooler than average.

Select national information is highlighted below. (Please note that different countries report anomalies with respect to different base periods. The information provided here is based directly upon these data):

Australia observed its eighth warmest March since national records began in 1910, due mainly to heat in the north and east of the country. Queensland was the hotspot, with its warmest maximum (anomalies of +2.88°C / +5.18°F), minimum (+1.62°C / +2.91°F), and mean (+1.89°C / +3.40°F) temperatures compared to the 1961–90 average in the 106-year period of record. Victoria and Tasmania were cooler than average for the month, while South Australia and Western Australia were close to average.
It was also a warm March in New Zealand thanks to frequent tropical airflow over the country, according to NIWA, with the national temperature for the month 1.0°C (1.8°F) above the 1981–2010 average. Many sites observed temperatures well above average (at least +1.2°C / +2.2°F).
In Sweden, March 2015 was cooler on average than the previous March; however, there was notable warmth in some areas. According to SMHI, a temperature of 18.7°C (65.6°F) was recorded in Oskarshamn, the highest temperature recorded in Sweden so early in the season. Stockholm reached 15.8°C (60.4°F), the highest temperature observed during the first half of March since records began there in the mid-1700s. A few stations at the northern Norrland coast were record warm for the month.
Finland had its third warmest March in its 116-year period of record, behind only 2007 and 2014. The highest temperature departures from average were more than 4°C (7°F), observed along the Ostrobothnian coastline, according to the Finnish Meteorological Institute.
In Iceland, the March 2015 temperature was 0.3°C (0.5°F) higher than the 1961–90 average, but 1.0°C (1.8°F) lower than the average of the past 10 years.

For the oceans, the March global sea surface temperature was 0.55°C (0.99°F) higher than the 20^th century average for the month. This marks the third highest globally-averaged March temperature in the 136-year period of record. Only March 1998 and 2010 ocean surface temperatures were warmer, with both months 0.56°C (1.01°F) higher than the 20^th century average. Record warm temperatures continued to dominate in the northeast Pacific Ocean and were also notable in the southwest Pacific and parts of the Arctic Seas to the north and northwest of Scandinavia. Overall, every major ocean basin had at least some areas with record warmth and large areas with much warmer-than-average temperatures. Also, continuing a pattern seen since fall 2014, much of the North Atlantic Ocean between Canada and the United Kingdom had much cooler-than-average temperatures during March, with an area of record cold observed within that that region.

El Niño conditions were present during March. Ocean temperatures in the Niño 3.4 region—the area between 5°N and 5°S latitude and 170°W to 120°W longitude where ENSO conditions are monitored—was +0.7°C (+0.11°F) during the last week of March, according to NOAA's Climate Prediction Center (CPC), indicating that a weak-phase El Niño is continuing. According to the CPC, there is about a 70 percent chance that El Niño will continue through Northern Hemisphere summer 2015, and more than 60 percent chance it will last through fall. El Niño conditions tend to enhance global temperatures, with stronger events having generally larger impacts.

March Global Land and Ocean plot

March Global Hemisphere plot

The most current data may be accessed via the Global Surface Temperature Anomalies page.

Year-to-date (January–March)

January–March Blended Land and Sea Surface Temperature Anomalies in degrees Celsius

January–March 2015 Blended Land and Sea Surface
Temperature Anomalies in degrees Celsius

January–March Blended Land and Sea Surface Temperature Percentiles

January–March 2015 Blended Land and Sea Surface
Temperature Percentiles

The first quarter of 2015 was the warmest such period on record across the world's land and ocean surfaces, at 0.82°C (1.48°F) above the 20^th century average, surpassing the previous record of 2002 by 0.05°C (0.09°F). The average global land surface temperature was also record high for the January–March period, at 1.59°C (2.86°F). Most of Europe, Asia, South America, eastern Africa, and western North America were much warmer than average, as shown by the Temperature Percentiles map above, with record warmth particularly notable in the western United States and eastern Siberia along the Verkhoyansk Range.

The average global ocean surface temperature for January–March was the third highest in the 136-year period of record, at 0.53°C (0.95°F) above average. The record highest temperature for the period was 0.56°C (1.01°F) above average, observed in both 1998 and 2010. Similar to March and indicative of how slowly temperatures change in the oceans compared with the land, record warmth for the three-month period was notable in the northeastern Pacific Ocean and the southwest Pacific east of Australia, while the North Atlantic between Canada and the United Kingdom was much cooler than average, with a record cold swath within that region. The unusual warmth in the northeast Pacific has been observed for well over a year.

January–March Global Land and Ocean plot

January–March Global Hemisphere plot

The most current data may be accessed via the Global Surface Temperature Anomalies page.

Precipitation

March

The maps below represent precipitation percent of normal (left, using a base period of 1961–1990) and precipitation percentiles (right, using the period of record) based on the GHCN dataset of land surface stations. As is typical, precipitation anomalies during March 2015 varied significantly around the world.

Torrential rainfall led to major flooding events in Angola in mid-March. The Angolan capital of Luanda was impacted on March 9^th while heavy rainfall and subsequent flooding hit Lobito three days later. At least 60 people were killed in Lobito and at least one person died due to the impacts of the floods in Luanda.
In northern Chile, unusually heavy rainfall near the end of March impacted the extremely dry regions of Atacama and Antofagasta. Some areas received well over their annual rainfall during this event. Antofagasta received 24.4 mm of rainfall in 24 hours during March 25–26, about the average rainfall expected over a 14-year period. Three people were killed by the impacts of the floods in Antofagasta and 23 people perished in Atacama.
At the end of March drought remained entrenched in the western United States, where mountain snowpack was record low for many locations in the Cascade and Sierra Nevada Mountains. Moderate to exceptional drought conditions were present across more than 98 percent of California, leading to unprecedented water restrictions in the state.