Climatological statistics for the normal period 1971-2000

The Finnish Meteorological Institute among many other meteorological institutes throughout Europe has published a climatological 30-year summary concerning the period of 1971-2000. The need of updated climatological 30-year statistics was obvious already in the end on 20th century. However, the former period 1961-1990 still remains the official normal period defined by WMO. The next official normal period is 1991-2020 but before that we will update the statistics for the period 1981-2010.

Locations

Helsinki (60° 10`N 24° 56`E) is the Capital of Finland and it is located nearby the southern coastal area. Jyväskylä (62° 24`N 25° 40`E ) is in the middle of Finland and Sodankylä (67° 22`N 26° 37`E) stays in the middle of Lapland. For more information about different regions, see the following page. Sodankylä is precisely under the number 19 in the figure.

Monthly statistics

The publication "Tilastoja Suomen ilmastosta 1971-2000 - Climatological statistics of Finland 1971-2000" contains information in three different types of tables. The first table type includes monthly average values and extremes for the temperature. It also contains the monthly average values for pressure, precipitation, relative humidity and average of snow depth on the 15th and last day of the month. Numbers of temperature- and precipitation days for all 114 stations are also published. Here are a few examples for Helsinki, Jyväskylä and Sodankylä.

Comparison between the months of January and July

The comparison of the mean temperatures of January (Tammikuu) and July (Heinäkuu) for the official and unofficial periods indicate the same as the comparison of winter and summer seasons.

From this table one can see some mean values for January and July for the offical and the unoffical periods.

The mean temperature for consecutive 10-year periods

Temperature is a continuously changing climatological factor. Diurnal variation gains a lot of attention but so do the longer time period oscillations as well. For instance the 10-year periods are quite an interesting tool for comparing longer time steps with each other. The next picture represents the 10-year mean temperatures for Helsinki Kaisaniemi, Jyväskylä and Sodankylä during the last century.

It is obvious from this picture that the 1930's was approximately as warm as the 1990's - actually it was some decimals warmer if only Jyväskylä and Sodankylä are taken into account. However the first decade of 2000 was warmer than the 1930's.

Mean temperatures do tell

As we compare the periods 1961-1990 and 1971-2000 with each other, we can easily find that there are no significant changes in the summer seasons to be seen. Meanwhile the influence of mild winters in the 1990's is quite clear. Almost everywhere in Finland the mean temperatures for the winter seasons 1971-2000 are one degree higher than for the offical normal period 1961-1990. But then again if we would choose to compare the normal period 1931-1960 to the period 1971-2000 we would get other kinds of results. However, it is a fact that the climate is warming and some effects can be seen already.

Precipitation remains the same

The amounts of precipitation of 1961-90 are very similar to the ones in 1971-2000.

The averages of annual temperature and precipitation in 1971-2000

The mean annual temperature and the average annual precipitation for the whole period 1971-2000 are visualized in a nationwide map format. These fields have been produced by using the so called kriging-analysis method. The resolution is not sufficient enough to bring out all the details for our knowledge but does however provide us with suggestive information. The Finnish Meteorological Institute has the possibility to produce more detailed information if needed.

Wind distribution

Table type 2 in the publication 1971-2000 includes the wind frequency distribution of all the 37 observation stations. In the example below you will find the wind distribution of Mustasaari Valassaaret situated in the Quark, the narrowest part of Sea of Bothnia.

Duration of sunshine