It has been very foggy lately.
The ships are sounding their horns loudly every morning.
The weather is getting warmer.
The degree of moisture in the air is getting higher.
All these tell us that Spring has arrived.
According to the Chinese Calendar, Sping Equinox (or Vernal Equinox) is today.
I always find that the Chinese Calendar is extremely accurate in telling the weather.
So it is.