The annual mean temperature of the year 2003 was in Southwestern Finland 5...6 degrees and elsewhere in the southern and central part of the country 3...4 degrees. In the province of Oulu and in the southern part of the province of Lapland the annual mean temperature was +0.5 ... +3 degrees, and in the northern part of the province of Lapland -1...+0.5 degrees. The annual mean temperature was very close to the long-term mean in a large part of the country. In the provinces of Oulu and Lapland, the annual mean temperature was about one degree higher than on the average.
The annual precipitation varied in the central and eastern parts of Finland between 600 and 760 millimetres. On the other hand, in the western and northern parts of the country it was 400-650 millimetres. The annual precipitation in the central, eastern and northern parts of Finland was in general quite close to the long-term average, but in the western part of the country less than usual. The deficit in annual precipitation was still largest in the province of Southwest Finland and in the western part of Uusimaa province. In the most southwestern part of Finland, the precipitation deficit was more than 100 millimetres from the average of the reference period of 1971-2000. Those months of the year with the least precipitation compared to the long-term average were February, March, July and September. In wide areas the monthly precipitation was above normal in May, August, October and December.
The Irene storm of April 5th was exceptionally strong with regard to its time of occurrence. After that, the whole summer season passed without storms. The first autumn storm, Mielikki, took place on September 23rd. In October there were only two storm days in the northern part of the Gulf of Bothnia, and in November there was none. A gale was blowing on December 11th. Since 1990 the number of days with storm in December was largest in 2003. After Christmas there were two of the most severe storms of the year, which caused material damage in the southern part of the country. Wind was at times dangerously strong also in land areas, causing for instance power cuts.
The sun shone for 1500-1800 hours. The amounts of sunshine hours were close to the averages of the reference period of 1971-2000. One could enjoy the sun most in Ahvenanmaa, where the sunshine hours amounted to nearly 2000. July was not only very hot but also very sunny on our coasts. After September, the end of the year was cloudier than usually when low pressure systems rolled out lots of clouds from the Atlantic to Finland.
The year began as exceptionally cold in the southern and central parts of Finland. The lowest temperature of the year, -41.9 degrees, was measured on January 7th in Kiutaköngäs in Kuusamo.
On the other hand, it was very mild in February in the north, as at the beginning of the month the weather became quickly milder in the whole country. The cause of the mild weather in Lapland was the often recurring föhn conditions, which occur when western or southwestern currents blow in the thick atmospheric layer across the Scandinavian mountain range. On the sheltering side of the mountain range, the downward wind of the föhn phenomenon dries and warms up the air close to the ground. The monthly precipitation of February was exceptionally small in the western part of the country.
April began as unusually cold in the whole country, and snow blizzards were still experienced in the southern part of the country at the beginning of the month. At Easter which coincided with April 20th the weather was very warm in the whole country with regard to the time of the year.
In July Finland enjoyed tropical days, and the experienced duration of continuous heat was record-breaking. Throughout the country, in July there were 26 days of heat at least somewhere in the country, in other words, the temperature rose in the afternoons above 25 degrees. There were daily maximum temperatures of over 30 degrees for 4-6 heat days in a row, during the first heat period that began on 14th July. The heat record of the summer and the whole year, 33.3 degrees, was measured in Mietoinen, the province of Southwestern Finland. Another peak heat period of 30 degrees began on July 28th and ended on August 1st. Now the conditions were similar to those in the tropics when the relative humidity was at the same time considerably high. The people in Finland lived a few days in very difficult conditions. Then in August the temperature decreased quickly back to typical. During the last week of August the temperature decreased to autumn cool temperatures. First snow fell in the south in October.
November was mild and there was little snow in the north. The average temperature in Lapland was even four degrees higher than on the average. The mild and rainy weather melted the snow cover away in Lapland at the beginning of the month. Even at the end of the month there was very little snow in the whole country. However, the land surface was white at the end of December, with the exception of the southern coast.
In our marine areas in December we had 11 storms rolled in by low pressure systems. The last low pressure systems of the year on December 28th and 29th brought with them strong storms. The last days of the year passed with extremely cold weather.
The period of winter, December 2002-February 2003, was exceptionally cold in the southern and central parts of Finland, but the level of cold winters during 1985-1987 was not reached. The winter mean temperature in Lapland deviated from the long-term mean and was only a little lower. Due to the especially scant precipitation in February, the precipitation of winter 2002-2003 remained smaller than usual in the southern and central parts of the country.
The spring (March-May) mean temperature deviated in Lapland and was higher, whereas in the southern part of Finland it was lower than normal. The precipitation in the spring was in general slightly above normal.
The summer (June-August) was somewhat warmer than normal, and in the eastern part of the country it was rather normal. The precipitation was slightly above normal in the eastern and partly in central parts of Finland, while in the coastal areas and in the whole of Northern Finland the precipitation was below normal.
The autumn (September-November) mean temperature was somewhat above normal. In a large part of the country and particularly in Southwestern Finland the monthly precipitation of September was well below normal and caused the precipitation of the whole autumn to remain below normal.