Signs of spring-winter

Looking up into the blue sky today there were cumulus clouds. The first I noticed were small puffy individual cumulus, a bit like a child's drawing of a cloud. A little later there were the windblown ones you see in the picture. So, what's special about this?
In our climate there are no cumulus clouds in winter. The sun is just not sufficiently warming. This is the first day in 2025 that the sun warms the forest enough to, in turn, warm the air around and over the forest, enough to create a bubble of warmer, more buoyant air, that rises into the sky far enough to cool down, condense, and create a cumulus cloud!
These day 1 cumulus clouds became a feature in my life when I flew a paraglider and they indicated a new flying season was here. I may no longer paraglide but the knowledge stays with me.
At midwinter The Red House and the kayak tent were in the shadow of the shadow of our house and nearby trees. Today's higher sun means shadows don't reach that far which means the The Red House veranda, the side of the camper van, and the front of the grey tent are all sun traps - places to sit for an hour or two in the warmth.
These are some signs that spring-winter is on the way, or perhaps has even arrived.