It is secure enough for "you". But for someone accessing it, it may not be secure.
This is topical, as a popular service is currently serving images of subscribers using http. As other subscribers "swipe" these images, they expose information about their "preferences" as the images can be seen by anyone sniffing the traffic.
If you are just hosting the weather it may not matter. Anyone typing in credentials should be concerned, and even with https or RDP inside a VPN they are not necessarily secure from sovereign agencies such as the NSA.
Being logged in to a Google account is not going to do them any favours either.
But this label does not mean your site is malicious or a threat, although a suggestible person may lead themselves to believe that is may be.