To implement the geographical and future climate adaptation of building moisture design for building projects, practitioners need efficient tools, such as precalculated climate indices to assess climate loads. Among them, the Frost Decay Exposure Index (FDEI) describes the risk of freezing damage for clay bricks in facades. Previously, the FDEI has been calculated for 12 locations in Norway using 1961–1990 measurements. The purpose of this study is both updating the FDEI values with new climate data and future scenarios and assessing how such indices may be suitable as a climate adaptation tool in building moisture safety design. The validity of FDEI as an expression of frost decay potential is outside the scope of this study. Historical data from the last normal period as well as future estimated climate data based on 10 different climate models forced by two emission scenarios (representative concentration pathways 4.5 and 8.5) have been analyzed. The results indicate an overall decline in FDEI values on average, due to increased winter temperatures leading to fewer freezing events. Further, the variability between climate models and scenarios necessitates explicit uncertainty evaluations, as single climate model calculations may result in misleading conclusions due to high variability between models.

With increasing temperatures in Norway, the possibility of heat waves are assumed to increase. The Norwegian Meteorological Institute (MET Norway) is testing ways to monitor heat waves  and possibly implement an operational warning system for heat waves in the future. For this work, it was necessary to assess the development of observed heat waves in Norway.Heat waves were computed from daily minimum and maximum temperatures for the period 1961-2020, for three example stations and maps. For the stations, time series were assessed. For the maps, an observation-based dataset on a 1×1 km grid was used. The two different normal periods 1961-1990 and 1991-2020 were also compared.The method to qualify a heat wave determines the number of heat waves in a given summer. There are different methods used internationally. MET Norway wants to find a method that works for Norway, and maybe in cooperation with surrounding countries. The last couple of years we have had the same criterias as used in Denmark; the mean value of maximum temperature of three consecutive days ≥ 28 degrees. In this study we have looked at different methods to qualify a heat wave in Norway, since the Danish method indicated heat waves too frequently, also during the spring. The method for heat waves is based on the maximum and minimum temperature combined. We have looked at different temperature limits and different number of days. For other weather warnings, a 2 years return period is used for a yellow warning. When testing different methods, we found that the mean value of maximum temperature for 5 days ≥ 28 degrees combined with the mean value of minimum temperature for 5 days ≥ 16 degrees were likely to occur seldom enough and also give some heat stress to people and nature.Climate services has worked together with the forecasting group at MET Norway to propose a method to use for both forecasting and climatology. This summer (2022) the heat wave monitoring system will be tested operationally, and an evaluation is due in the autumn.

The temperature is increasing historically and is projected to rise in future scenarios. This trend is evident both globally and locally in Norway. In Norway, the temperature has increased by about 1.3 degrees Celsius since 1900 and is expected to continue increasing in the future. Changing temperature, and the impacts on various climate indices, are affecting all parts of the society. Here different temperature indices are studied. Changing temperature affects, among other things, infrastructure, such as roads and buildings. This leads to changes in for instance design values, which again affects the requirements for buildings, such as insulation, cooling and heating. To study temperature indices, observation based and bias-adjusted daily climate projections with a 1km grid resolution that covers mainland Norway are used. For the two historical normal periods 1961-1990 and 1991-2020, and for the future climate in the periods 2041-2070 and 2071-2100, for three scenarios RCP2.6, RCP4.5 and SSP3-7.0. The result shows for example fewer days with freezing temperatures and more summer days in Norway. Other temperature indices that are studied are climatological seasons, growing season, heat waves, tropical days and days with zero crossings. Mainland Norway stretches from about 58 °N to 71 °N, has a long coastline in the west, high mountains and steep valleys, this leads to huge variations throughout the country and seasons. This affects the temperature indices and are clearly visible in the maps. The Norwegian Centre for Climate Services (NCCS) provides information for climate adaptation and helps municipalities to be robust in a changing climate. Information about changes in temperature indices can be of help and background information for climate adaptation. All authors in this abstract are connected to NCCS.

Snow loads are an important consideration in the design of buildings. Particularly in parts of Norway where heavy snowfall is common, it is important to know the weight from snow on houses to avoid structural damage or collapse. National standards and building regulations have been focusing on snow loads since 1949, and these regulations have been revised several times. The Norwegian Meteorological Institute (MET Norway) produces daily interpolated data sets of precipitation and temperature with a 1*1 km resolution as part of our regular service. Data from 1957 - dd are included. These data sets are then used by the Norwegian Water Resources and Energy Directorate (NVE) to generate "Snow Water Equivalent" (SWE) interpolated data sets, grids, using a hydrological model. In this study, the SWE grids are used to produce snow loads with a 50 year return period for Norway, for two different periods 1961-1990 and 1991-2020. Three different methods for calculating the 50-year return period of snow loads are compared. In addition, the old normal period, 1961-1990, is compared with the current normal period, 1991-2020. It is typically shown that the snow load decreases in the lower-lying areas and along the coast of Norway. In higher altitude areas and in parts of Northern Norway, where there still are cold winters, the snow loads have increased. Snow loads are also extracted for each municipality center in Norway, to compare to the current national snow loads standard. This method is suggested, and about to be adopted, for future use in the design of buildings in Norway.

Due to increasing temperature, the growing season is expanding in Norway, with the exception of glaciers and high mountains.The growing season starts earlier or ends later in the year, when temperatures during night can be low. Therefore, a longer growing season, despite a decreasing number of frost days in a generally warmer climate, may lead to an increased risk of frost early or late in the growing season. Frost early in the growing season can be a risk for several plant species. There have been incidents in Norway where fruit farmers have had their crops destroyed after an unusually warm period followed by a cold spell. This is the first study on frost days at the start of the growing season where all of mainland Norway is included. To study frost days in the growing season, observation based gridded data at daily resolution is used for two historical normal periods (1961-1990 and 1991-2020) with a 1 km grid resolution covering mainland Norway. Additionally, bias-adjusted daily climate projections are analysed for the periods 2041-2070 and 2071-2100, following three different future climate scenarios (RCP2.6, RCP4.5 and SSP3-7.0). Frost in the growing season is a risk factor in the lower areas in Southern Norway today, with the highest risk in the southeast. Changes between the historical normal periods show the highest increase of days along the coast in the west of Southern Norway. This is the same area where the growing season has increased the most. Future scenarios show an even higher risk of frost days in the growing season along the coast of Norway except for the northern most areas. Again the increase of the risk is highest in the same areas where the growing season is calculated to increase the most. This work is done within the Norwegian Centre for Climate Services (NCCS). NCCS provides information for climate adaptation and helps municipalities to be robust in a changing climate. Information on the changing growing season and risk of frost days in the growing season can be of help to farmers and used as background information for climate adaptation. All authors in this abstract are connected to NCCS.

Due to increasing temperatures, the growing season is expanding in Norway, except on glaciers and in high mountain areas. It now starts earlier and ends later in the year, when night–time temperatures may still be low. Therefore, despite a decreasing number of frost days in a generally warmer climate, a longer growing season may lead to an increased risk of frost early or late in the growing season. Frost early in the growing season can pose a risk for several plant species. In Norway, there have been incidents where fruit crops were destroyed after an unusually warm period followed by a cold spell. In this study, we show that frost in the beginning of the growing season is already a risk factor in lowland areas of South Norway, with the highest risk in the southeast. Changes between the periods 1961–1990 and 1991–2020 show the largest increase in the number of days along the west coast of South Norway, which is also where the growing season has increased the most. Future scenarios indicate an even higher risk of frost days in the beginning of the growing season along the coast of Norway, except in the northernmost areas. The increase in risk is highest in the same areas where the growing season is projected to increase the most. In contrast, the risk decreases in many inland areas of South Norway.