It was also a very hot summer in many other parts of Eurasia and northern Africa. The Russian Far East had temperatures well above normal, which combined with the extreme heat in the west to result in the hottest summer on record averaged over Russia as a whole. Japan and China also had their hottest summers on record. Earlier in the year, there was exceptional pre-monsoon heat in southern Asia, which included a temperature of 53.5°C at MohenjoDaro on 26 May, a national record for Pakistan and the highest temperature in Asia since at least 1942. Extreme heat affected northern Africa and the Arabian Peninsula at times during the summer, with notable readings including 52.0°C at Jeddah (Saudi Arabia), 50.4°C at Doha (Qatar) and 47.7°C at Taroudant (Morocco).
Abnormal Winter in Many Parts of the Northern Hemisphere
The normal mid-latitude westerly flow was unusually weak during the 2009-10 northern hemisphere winter, which resulted in many substantial climate anomalies in various parts of the hemisphere. In particular, it was a rather cold winter over most of Europe (except the Mediterranean region), the Asian part of Russia (except for the Far East) and Mongolia. The peak winter temperature anomalies (below -4°C) were in central Russia, but in a historical context, the most unusual conditions were on the western periphery of Europe, with Ireland and Scotland both experiencing their coldest winter since 1962-63. Many other parts of northern and central Europe had their coldest winter since 1978-79, 1986-87 or 1995-96, although the temperatures were generally not exceptional in a long-term historical context. The lack of the normal winter westerlies also resulted in dry conditions in normally high-rainfall coastal areas, with western Norway having its driest winter on record (72% below normal). While strong westerly winds were infrequent for most of the winter, a severe winter storm (Xynthia) crossed north-western Europe at the end of February, causing wide-spread wind and storm surge damage, especially in France where wind speeds exceeded 150 km/h on the west coast. Further south in Europe, it was a very wet winter, with precipitation widely 100% or more above normal over Spain, Portugal, Italy and south-eastern Europe.
Northern Africa recorded warm conditions during winter. February temperatures averaged 3.7°C above the long-term average over the Saharan/Arabian region, the largest anomaly on record for any month. In late February, temperatures reached between 30 and 36 °C in northern Algeria, the highest for February since 1980. Winter temperatures were also well above normal over Turkey and the Middle East.
In North America, the normal north-south gradient of temperature was much weaker than normal. Canada had its warmest winter on record, with national temperatures +4.0°C above the long-term average; winter temperatures were 6°C or more above normal in parts of the country’s north. (It went on also to have its warmest spring on record, with temperatures +4.1°C above the long-term average). The warm conditions extended further east in the Arctic to cover Greenland and Spitsbergen. Canada also had its driest winter on record, with especially abnormal dry conditions in British Columbia (which combined with unusually high temperatures to cause poor snow conditions for some events at the Winter Olympics in Vancouver). In contrast, most of the continental United States (except for the far north-west and north-east) was colder than normal. For the United States as a whole, it was the coldest winter since 1984-85, and most southern areas from Texas eastwards had one of their 10 coldest winters on record. These cold conditions were accompanied by unusually extensive snow cover, and very heavy seasonal snowfall amounts in some eastern cities, including a record seasonal total in Washington D.C.
Heavy Rains and Flooding
Large parts of Indonesia and Australia experienced heavy rains in 2010 as a La Niña event developed, with particularly unusual rains from May onwards (normally the driest time of the year). In Indonesia, at least double the normal monthly rainfall fell in each of the months from June to October in most of Java, the islands east of Java and southern Sulawesi. The May-October period was the wettest on record for northern Australia with rainfall 152% above normal, while above-normal rains further south contributed to an easing of long-term drought in parts of the south-east. The spring was especially wet, and averaged over Australia was the wettest on record.
Whilst seasonal rainfall was not as persistently above normal further north in south-east Asia, both Thailand and Vietnam experienced major floods in October with significant loss of life and economic damage.
Many other parts of the world were affected by significant floods during 2010. An active wet summer monsoon season in the West African Sahel was accompanied by floods from time to time, with Benin and Niger the countries most severely affected. In Benin, this caused the worst flooding on record in terms of impact, causing severe losses to the agriculture sector and severe disturbances to public services, including cutting access to health centres, although rainfall amounts themselves were mostly not record-breaking.
Central Europe had major floods in May, particularly in eastern Germany, Poland and Slovakia; in late June flooding occurred in Romania, Ukraine and Moldova, and later Germany had its wettest August on record. Bursa (Turkey) had its wettest January-October on record (1152 mm, 132% above normal), while precipitation averaged over Romania for the January-October period was 34% above normal, and the northern Bohemia region (Czech Republic) had its wettest year since 1981.
In South America, Colombia had its most severe floods in more than 30 years in November. More localized flash floods caused severe damage and loss of life in numerous other locations, including Rio de Janeiro, Brazil (April), Madeira (February), Arkansas, United States (June) and southern France (June).
