That is why the surface temperature usually drops very little during the night when stratus clouds persist. For the same reason, dew or frost first forms in open areas. On many frosty autumn mornings, you can observe frost-free ground under trees that still have leaves. These arguments work when radiative effects control temperature changes. Let's examine the second explanation.
Heat is released only if water vapor condenses.
In this case, there is no latent heat release. The formation of dew or frost does release latent heat. The net rate of cooling at the ground is thus governed much more by radiation received from other objects than from the formation of frost.