Graphical Climatology of Helsinki, Finland: Daily Temperatures and Rainfall, by Year (1959 – Present)

The following is a graphical climatology of Helsinki, Finland (Vantaa station) temperatures and precipitation, from 1959 into 2017. Included are summary overview charts followed by 59 year-to-year graphs depicting daily temperatures, temperature anomalies, and precipitation. Snowfall observations are not available for this particular station. Presently, the available data set covers 1959 to 2017, inclusive. The temperature and precipitation data are converted from metric units to (rounded) degrees F, and inches, respectively.

Data were accessed from the European Climate Assessment & Dataset project (ECAD) online site, and the following recommended attribution is provided: “Klein Tank, A.M.G. and Coauthors, 2002. Daily dataset of 20th-century surface air temperature and precipitation series for the European Climate Assessment. Int. J. of Climatol., 22, 1441-1453. Data and metadata available at http://www.ecad.eu”

“This is the series (SOUID: 142079) of FINLAND, VANTAA HELSINKI-VANTAAN LENTOASEMA (STAID: 6992)”.

In addition to the daily temperature and precipitation floating bar charts, hour-by-month “climogram” charts are provided, portraying diurnal/seasonal variations of selected parameters on single-page grid-layouts analogous to topographic maps. These are derived from downloaded raw hourly observational data from the NOAA NCDC’s “Access to Global Hourly Surface Data” online site.

Author: Charles Fisk e-mail contact: cjfisk@att.net

CLIMATE OVERVIEW GRAPHS

HELSINKI MISCELLANEOUS CLIMATOLOGICAL RAINFALL & TEMPERATURE GRAPHS

HOUR-BY-MONTH CLIMOGRAMS FOR HELSINKI

YEAR-TO-YEAR GRAPHS – INTERPRETATION

The uppermost chart for a given year’s page (accessed by the links below) are “floating-bars” of the year’s daily maxima and minima temperatures (in Deg F). The bars depict the varying diurnal, synoptic, long-wave, and seasonal temperature anomaly influences on Helsinki temperature over the course of the year, and aside from their physical interpretations the patterns can be occasionally, for their own sake, be rather interesting to scan/examine. In this regard, a subset link collection of some of the more distinctive individual years’ configurations (n=26) are listed chronologically in the last section below.

The second chart down shows the day-to-day mean temperature anomalies (daily mean temperature less the corresponding long-term 1959-2017 climatological mean). Vertical lines extending upward from the zero line indicate above average means for the day (colored red), those extending downward indicate below average daily means (colored blue).

The third chart down shows the second chart’s anomalies in deseasonalized (“standardized”) form. This adjusts for the fact that individual calendar days have higher or lower inherent year-to-year variability in mean temperature. To create a common relative anomaly scale for each day, the anomalies are divided by their corresponding calendar day standard deviations to generate “standardized departures” or “z-scores”. Greatest positive standardized departure in the 1959-2017 Helsinki record is +3.21 z for 8 Aug 2010, greatest negative –4.02 z for 30 Dec 1978.

The bottom chart depicts daily precipitation totals, as high as 2.58 inches (9 Jul 1996).

It should be mentioned that clicking on the yearly floating-bar charts a second time after they appear on the screen will enlarge them even further.

YEAR-TO-YEAR GRAPHS – COMPLETE SET OF LINKS

1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017

SELECTED YEARS’ WITH SOME OF THE MORE INTERESTING PATTERNS

1962 – Wettest Year (35.91″) of 1959 to 2017 history.
1963 – Coldest March of ’59-’17 record, Driest Spring (Mar-May: 1.57″) of history
1965 – Pronounced cold spells, usually several weeks’ duration, throughout the year.

1966 – Very Cold January to mid-February.

1967 – Very Cold January & December.

1968 – Another cold January. Oscillating temperature spells, both warm and cold, over balance of year.
1973 – Cold spells, progressively more anomalous, from mid-August on. Great one-day temperature surge over 9-10 December: Max temp -8 F on the 8th, 36 F on the 9th. Daily temperature range on 10th: -18 F to +36 F.
1974 – Very mild January-March Mostly cool Spring & Summer. Record Wet Fall (Sep.-Nov. – 14.66″). No subzero temperatures during the year (minimum: + 6 F)
1976 – Coldest Year to date (mean: 37.7 F). Driest Year (16.63″) of 1959-2017 period

1978 – Intense cold closes the year. Coldest December of 1959-2017 period (9.0 F) and coldest year thus far overall (37.3 F).

1985 – Very Cold January & February. Coldest Year of 1959-2017 record (36.8 F)

1987 – Great Cold Spell in January. Temperatures no higher than -12 F over the 5th to 12th, no higher than -20 F over the 9th to 12th. Max/Min on 9th and 10th: -26F/-30F and -24F/-32F, respectively, with daily mean departures as great as -50 F. Monthly mean only 0.5 F – Coldest calendar month post-1959.

1989 – Mildest January to March period on record (32.8 F) and warmest year of at least the last 30 – 43.5 F). Commencement of dramatic warm shift in annual mean temperatures: 24 of next 29 years including ’89 warmer than 1959-2017 mean (41.2 F) – see time-series

1990 – Very Mild January to April.

1992 – Another mild January to March

1993 – Warmest May to date (55.6 F). Average daily temperature range in May 23.8 F – highest on record; just 3 precipitation-days. Abrupt turn to colder than average temps in late May, to predominate over balance of year.

1994 – Wettest Spring on record (7.67″). First 90 F of post-1959 period, on 27-July

2000 – Mildest October-December on record (40.4 F), warmest year to date (44.2 F).

2002 – Persistent well above average daily temperatures thru early September, abrupt shift to colder than average thru year-end.

2006 – Driest Summer (June-August: 2.76″ prcp). Warmest August-October period (61.3 F) of the history.

2008 – Warmest Year to date (44.7 F). January and February each warmer than March.

2010 – Warmest calendar month (July) of history (72.7 F); also warmest Summer to date (Jun-Aug); 93 F on 28 July, warmest day of ’59-’17 period. Max/Min on 8 August: 89 F/71 F).

2011 – Cold February, but warmest Summer (surpasses 2010 by 0.2 F) AND Fall to date.

2012 – Wettest year (34.58″) since 1962.

2014 – Gyrating temperature anomaly spells, both warm and cold over first half of year.

2015 – Warmest Year to date (45.0 F). No subzero temperatures all year (lowest +2 F).