Go ahead, there's no harm this time of year.
On the right is the typical power pulley. The smaller one is called a dry sump power pulley because it's so small, a dry sump multi-stage oil pump can stick out beyond it. Obviously, the dry sump pulley slows the fan even more than the power pulley on the right.
The dry sump pulley is what I am using right now. Even with that, my engine is OVERCOOLED.
Been doing this for years. Once the daytime temps get above 15