The German Weather Service will publish the climate data including the in early 2026. Global radiation for the year 2025. The average annual sum in Germany was around 1.187 kWh/m². This makes 2025 one of the years with the most solar radiation since systematic evaluations began in 1983 and places it fourth in historical comparison. At the same time, the value is significantly above the long-term average of the reference period 1991–2020.
Especially the First half of the year 2025 contributed significantly to this outcome. Several months recorded above-average radiation levels, resulting in high cumulative global radiation early in the year.
Sunniest months of the year in 2025
Spring 2025 was above average in terms of sunshine, and particularly high radiation levels were reached June and August. With an average of 187 kWh/m², June alone was about 13% above the long-term average since records began. In contrast, individual months such as May, July, and September, as well as the months toward the end of the year, were somewhat weaker. Nevertheless, the first half of the year, which was very sunny overall, more than offset these fluctuations, so that the annual total was well above the long-term average.
Regional Distribution of Global Solar Radiation 2025
The spatial distribution of global radiation in 2025 largely followed the long-term climatological pattern in Germany. Typically, a clear gradient is observed with increasing radiation sums from northwest to southeast.
The smallest annual totals were registered in the northern federal states and the low mountain ranges, especially in Schleswig-Holstein, Mecklenburg-Western Pomerania, and parts of Lower Saxony. There, the annual values ranged between 1,050 and 1,150 kWh/m². The primary reason for this is a generally higher cloud cover and shorter sunshine duration on average throughout the year.
The highest values In 2025, there were rallies against this in southern German regions. Particularly in Saarland, the Rhine-Neckar region, Breisgau as far as Lake Constance, and the Bavarian Forest. There, the global radiation reached an average of up to 1,350 kWh/m² annually. These regions, in particular, are regularly among the sunniest areas in Germany due to their climatic conditions.
Comparison of the most radioactive years since measurements began
With an average annual total of 1,187 kWh/m², global radiation in 2025 ranks among the sunniest years since reliable evaluations began. The highest values of recent decades were always reached in particularly sunny years.
| Year | Ø Global irradiation (kWh/m²) | Classification |
| 2022 | 1.227 | Record year so far |
| 2018 | 1.207 | 2nd place – exceptionally high |
| 2003 | 1.197 | 3rd place – with a record summer & very radiant |
| 2025 | 1.187 | 4th place since measurements began |
| 2024 | 1.113 | High compared to the 90s |
Compared to the long-term average of the reference period 1991–2020 global radiation around 2025 100 kWh/m² above. This confirms the trend of rising radiation levels in Germany observed for several decades.
Global Radiation 2025: Very good conditions for PV systems
The year 2025 is among the years with the highest solar radiation since systematic measurements began, confirming the long-term trend of increasing global solar radiation in Germany. The exceptionally sunny first half of the year already laid the foundation for the high annual total early on.
Years like these offer particularly favorable conditions for the use of solar energy. High global radiation has an immediate positive impact on the electricity yields of photovoltaic systems and underscores the importance of solar irradiance as a key metric for assessing photovoltaic potential.
Further information can also be found in our posts on Global radiation 2024, Energy weather 2023 and Global radiation 2022 as well as to PV yield & profitability.