Similar to how any structure affects the area immediately surrounding it, solar photovoltaic panels can affect the climate of the area directly beneath the module or right next to it. The structure can trap heat below it and prevent evaporation from the soil, which in turn can increase the temperature near the panel (typically by less than 1 degree) and can increase the humidity below the panel.
This microclimate below the panel can be helpful for growing plants in some areas and can lend itself to the planting of environmentally beneficial vegetation under solar arrays, such as pollinator-friendly or native vegetation. There is also a growing field of research focused on the co-location of agricultural production and photovoltaics, known as agrivoltaics.
Solar thermal panels, a much less common type of solar panel can have a much greater effect on the climate.