DOI: 10.57707/fmi-b2share.19be1dd18c1c4db789f068980732f3ee
title: 30-year time series of weather variables at hourly resolution for the recent past and future climates in Finland

description: This archive contains 30-year time series of nine weather variables at hourly resolution for Vantaa, Jokioinen, Jyväskylä and Sodankylä. In addition to the recent past (1989–2018), datasets are provided for three future periods under the RCP2.6, RCP4.5 and RCP8.5 greenhouse gas concentration pathways.
description: Meteorological datasets described here have been compiled for four weather stations in Finland: Vantaa, Jokioinen, Jyväskylä and Sodankylä. The datasets can be regarded as extended RASMI datasets, and they contain 30-year time series at hourly resolution of the following variables: air temperature, relative humidity, wind speed and direction, global and diffuse horizontal irradiance, direct normal irradiance, precipitation, and atmospheric downward longwave radiation. The datasets for the recent past climate comprise years 1989–2018. The datasets for weather variations in projected future climates include three periods, 2015–2044, 2035–2064 and 2065–2094, referred to according to their mid-point years, i.e., 2030, 2050 and 2080, respectively. All the time series representing potential future climates were compiled for three representative concentration pathways: RCP2.6 representing small, RCP4.5 medium, and RCP8.5 very large greenhouse gas emissions.
description: The number of the 30-year hourly datasets is ten for each location: one dataset for the recent past period, being derived from observations, and three datasets, each corresponding to one of three alternative RCPs considered here, for each of three future periods. Hence, the total number of the data files is 40.

The data files are named as follows:
“Place”_”period” or “Place”_”scenario”-“mid-point year”
where
Place: Jok (for Jokioinen), Jyv (for Jyväskylä), Sod (for Sodankylä) and Van (for Vantaa)
period: 1989-2018
scenario: RCP26, RCP45 or RCP85
mid-point year: 2030, 2050 or 2080 

The format of the data files is Text/CSV (comma separated values), and their structure is as follows:
t_fin, Te, RHe_water, ws, wd, Rglob, Rdif, Rbeam, precip, LWdn
where
1. [t_fin]: Standard time (wintertime) in Finland (Eastern European Time, EET): year-month-day hour:minute:seconds. Note that in the datasets for future periods, as well, t_fin refers to the time of the historical observations that were then transformed to represent future climates. 
2. [Te]: Outdoor air temperature at a height of 2 m above ground level (T2m), instantaneous value, unit ºC
3. [RHe_water]: Outdoor air relative humidity with respect to liquid water (RH) at a height of 2 m height above the ground surface, instantaneous value, unit %
4. [ws]: Wind speed at a height of 10 m height, instantaneous scalar value, unit m s-1 
5. [wd]: Wind direction, positive clockwise from the north, instantaneous value, unit º. 90º: wind is blowing from the east, 180º: from the south, 270º: from the west, 360º: from the north, 0 calm.
6. [Rglob]: Global horizontal irradiance (GHI), average value after the previous time point, unit W m-2. For example, a value at 15:00 indicates an average value between 14:00 and 15:00.
7. [Rdif]: Diffuse horizontal irradiance (DHI), average value after the previous time point, unit W m-2. 
8. [Rbeam]: Direct normal irradiance (DNI), average value after the previous time point, the receiving surface being normal to the solar direction, unit W m-2.
9. [precip]: Total precipitation (liquid, solid or a mixture) reaching the horizontal ground surface, cumulative value from previous time point, unit mm h-1 (equal to kg m-2 h-1).
10. [LWdn]: Atmospheric downward longwave irradiance, unit W m-2.
description: For each of three future periods, the observational dataset at a location under consideration was transformed to represent future climate by modifying the hourly values of the weather variables in accordance with CMIP5 climate model projections under the three alternative RCPs. Various so-called delta change methods were used to construct the future hourly values of the variables. Descriptions in Finnish are given in reports by Jylhä et al. (2020) and Laukkarinen at al. (2022). For information in English, see Lehtonen et al. (2014), Jylhä et al. (2015) and Jylhä and Ruosteenoja (in preparation). Background information about the projected climate change in Finland during the 21st century calculated from CMIP5 global climate model simulations under RCP greenhouse gas scenarios is provided by Ruosteenoja et al. (2016). 

The archive additionally includes the following methodological documents:
• Calculations of hourly solar irradiances from measured data (Böök and Lindfors, 2025) 
• Constructing time series of 1-hour precipitation from weather codes and 12-hour precipitation sums (Jylhä, 2025). 
• Constructing hourly atmospheric downward long-wave radiation values for future climates by combining in-situ, reanalysis and climate model data with a machine learning method (Laukkarinen et al. 2025). 

References:

Böök, H., Lindfors, A., 2025: Calculations of hourly solar irradiances from measured data. In: Jylhä, K., Böök, H., Laukkarinen, A., Lindfors, A., Ruosteenoja, K., Vinha, J: 30-year time series of weather variables at hourly resolution for the recent past and future climates in Finland. [Dataset]. Finnish Meteorological Institute. doi: 10.57707/fmi-b2share.19be1dd18c1c4db789f068980732f3ee

Jylhä, K., 2025: Constructing time series of 1-hour precipitation from weather codes and 12-hour precipitation sums. In: Jylhä, K., Böök., H., Laukkarinen, A., Lindfors, A., Ruosteenoja, K., Vinha, J.: 30-year time series of weather variables at hourly resolution for the recent past and future climates in Finland. [Dataset]. Finnish Meteorological Institute. doi: 10.57707/fmi-b2share.19be1dd18c1c4db789f068980732f3ee

Jylhä, K., Ruosteenoja, K.: Development of hourly weather files for building performance simulations – Part 2: Projected future climates. Manuscript in preparation.

Jylhä, K., Ruosteenoja, K., Böök, H., Lindfors, A., Pirinen, P., Laapas, M., Mäkelä, A., 2020: Nykyisen ja tulevan ilmaston säätietoja rakennusfysikaalisia laskelmia ja energialaskennan testivuotta 2020 varten. (Weather data for building-physical studies and the building energy reference year 2020 in a changing climate). Finnish Meteorological Institute, Reports 2020:6. 81 p. (In Finnish with abstract in English and Swedish). https://doi.org/10.35614/isbn.9789523361287

Laukkarinen, A., Jokela, T., Vinha, J., Pakkala, T., Lahdensivu, J., Lestinen, S., Jokisalo, J., Kosonen, R., Lindfors, A., Ruosteenoja, K., Jylhä, K., 2022: Vaipparakenteiden rakennusfysikaalisen toimivuuden ja huonetilojen kesäaikaisen jäähdytystehontarpeen mitoitusolosuhteet: RAMI-hankkeen loppuraportti. (Climatic design conditions for the heat and moisture behaviour of building envelope structures and summer-time cooling need of buildings – Final report of the RAMI project.) Tampere University. Civil Engineering. Research report 3. 192 p (In Finnish with abstract in English.) https://urn.fi/URN:ISBN:978-952-03-2438-4

Laukkarinen, A., Lindfors, A., Ruosteenoja, K., Jylhä, K., Vinha, J., 2025: Constructing hourly atmospheric downward long-wave radiation values for future climates by combining in-situ, reanalysis and climate model data with a machine learning method. In: Jylhä, K., Böök, H., Laukkarinen, A., Lindfors, A., Ruosteenoja, K., Vinha, J.: 30-year time series of weather variables at hourly resolution for the recent past and future climates in Finland. [Dataset]. Finnish Meteorological Institute. doi: 10.57707/fmi-b2share.19be1dd18c1c4db789f068980732f3ee

Lehtonen, I., Ruosteenoja, K., Venäläinen, A., Gregow, H., 2014: The projected 21st century forest-fire risk in Finland under different greenhouse gas scenarios. Boreal Environment Research, 19(2), 127–139. http://hdl.handle.net/10138/228540

Ruosteenoja K., Jylhä K., Kämäräinen M., 2016: Climate projections for Finland under the RCP forcing scenarios. Geophysica, 51, 17-50. http://www.geophysica.fi/pdf/geophysica_2016_51_1-2_017_ruosteenoja.pdf

How to cite:
Jylhä, K., Böök, H., Laukkarinen, A., Lindfors, A., Ruosteenoja, K. and Vinha, J. (2025). 30-year time series of weather variables at hourly resolution for the recent past and future climates in Finland [data set]. Finnish Meteorological Institute. https://doi.org/10.57707/FMI-B2SHARE.19BE1DD18C1C4DB789F068980732F3EE