In terms of temperatures, the year 2002 was divided into two in Finland. The period January-August was warmer than average almost throughout the country. Of the summer months, August reached record warmth in the southern part of the country. However, the warm weather ended quite quickly half way through September. Compared to long-term averages the rest of the year was cold or very cold.
The average annual temperature in Southern Finland was 5...6.5 °C, and in Central Finland and Province of Oulu it was 3...4.5 °C. In Province of Lapland the average annual temperature was +1.5...-1.5 °C. The average temperature for the year was for the country as a whole 0.0... 0.7 °C higher than the average for the reference period of 1971-2000. It is extremely exceptional that the weather of eight consecutive months, when compared to long-term averages, is very mild or record warm and that the remaining months of the year are cold or very cold.
Another extremely significant feature of the weather in 2002 was the low precipitation on the south coast, in Southwestern Finland and in parts of Western Finland. Combined with the high evaporation rates for July and August, this resulted in places in severe drought on nearing the end of the year. The drought was at its severest along the coastline. At its lowest, the annual precipitation on the mainland dropped to about 400 mm, which is only slightly over half of the longterm average, especially along southern and southwestern coastline.
The beginning of the year was characterised by the unusually frequent occurrence of rain and drizzle, in addition to the snow, in January and February; this extended all the way up to Lapland. The average temperatures for December and January for the country as a whole were 1.5...2 °C higher than the average for the reference period of 1961-1990. December was the coldest of the mid-winter months for the winter 2001-2002, which is extremely rare. Late winter, March-April, was very sunny, but there were a few blizzards interrupting the sunny period. By the end of March, snow melted away completely in the southwestern parts of the country and along the west coast almost as far as Oulu.
Thermal spring, the period when the average diurnal temperature stays above zero, began in the southern and central parts of the country on March 26, which is earlier than average, and in the northern part also very early, by the end of the first week of April. On a couple of occasions, the weather was record warm in April. There was hardly any rain in April. The dry period of very little rain began already in mid-March and continued for more than six weeks.
Thermal growing season, the period when the average diurnal temperature stays above +5 °C, began in the southern and central parts of the country soon after mid-April and in Southern Lapland before the end of April. Thus the growing season began 1.5-2 weeks earlier than on average. The beginning of May was very warm. Mid-way into the month the weather became especially cold in Northern Finland. Snow fell down in regions such as Kainuu and Koillismaa (Northeastern Finland). Frost was severe at times as far down south as Southwestern Finland. The end of the month was very warm again. The heat-waves of May 28-30 in Central and Northern Lapland set new records. There was only a little rain along the coastlines and in Lapland, in places less than 10 mm. Elsewhere in the country, there were heavy, short-lived showers.
A sweltering summer
June was at first very warm and sunny, but the end of the month rainy and cool. Except for Lapland, July was very hot in the rest of the country. July 4 was characterised by storms were in the evening; in Uusimaa, the storms were violent. One day later powerful thunder and lightning accompanied by gusts of stormy weather and heavy showers caused major material damage and hazardous situations especially in the eastern part of the country. Violent storms battered the Oulu region. This stormy weather was followed by a period of very little rain in many places, which persisted for until the end of summer.
August was dry and record warm. The southern and western parts of the country enjoyed a record number of hot days for August; between 10 and 17 depending on the locality. August provided a new national record for the average monthly temperature; 20.9 °C was measured in Utö. Helsinki-Vantaa's 19.3 °C was the new record for this locality for the month of August. The period June up to and including August was the second warmest on average in most parts of the country for the long-term period since the beginning of the 1900s; it was even warmer in 1997 or 1972. The southern and central parts of the country enjoyed a record number of hot days, between 20 and 35. The end of the summer was characterised by severe drought; this was especially so in the coastal regions.
There were considerably few storms connected to lows. There were only 10 stormy days in Finland's sea territory while the annual average is 22 storms. There were a lot of sunny days between April and August in the southern and central parts. The sunniest month in Lapland was June.
There were some hot days right up to the early days of September, but night-time frosts were a reality at the end of the month. The latest occurrence of a temperature in excess of 25 °C is now September 9; this was when the thermometer in Mietoinen, in Southwestern Finland, read 25.2 °C. Frosts became part of the local weather in Western Finland as early as September 11. September in the southern and central parts of the country and at the top of the Gulf of Bothnia was characterised by its low rainfall figures.
The shift over to thermal autumn took place in a flash between September 12-18. The onset of autumn in the north of the country was a couple of weeks later in coming than on average; in the southern and central parts of the country the thermal autumn began at a typical time. The thermal autumn was a record short one, just 4-5 weeks in length. Normally autumn lasts some two months.
The thermal growing season also ended very early throughout the country; in Central and Northern Finland it ended about September 20 and in Southern Finland at the end of the month. The average temperature for September-November in Southern and Central Finland was record-low. Depending on the part of the country in question, the autumn of 2002 was among the 2-9 of the coldest since the year 1900.
Early and cold winter
The record-cold October brought in the snow early. In terms of average monthly temperature, October was in places a record-cold October since regular records began to be kept in 1900. There was very little precipitation in October over wide areas. Throughout the country, thermal winter began mid-way through October, which was record early for the southern parts. November was also very cold. There were several blizzards in the latter half of November. The snow cover in the central and eastern parts of the country increased to over half a metre, which was meant 20-30 cm over the average for this point in time. November had a fairly typical amount of precipitation.
December was very cold. The -40 °C or so temperature measured during the last days of the year in the northern parts of the country went into the books as new local records. December was also conspicuous for its low snowfall figures. Southwestern Finland received a mere 10% of its average precipitation. In Lapland, precipitation was generally less than half of the average. The snow depth was extremely large in the central and eastern parts of Finland throughout December.