Houndour, Snubbull and Swinub from hatching eggs?

Just out of curiousity...are you south of the equator?
I am wondering if you are in Summer at the moment.

The reason I ask is that day/night apparently makes a difference to spawns (I see Houndoor at night, but rarely during the day), climactic conditions effect spawns (see Corsola) and I am wondering if some may be 'seasonal'. Specifically Swinubs.
I have not seen any, while others complain about being over run - but I am in the 'summer', so perhaps I will need to wait until winter to see Swinubs.

...or I will just never see them.

In Europe you cannot make a single step without encountering a ******* Swinub.

edit: To be more precise, I'm from Austria. No reason for downvoting, they are everywhere here, although this doesn't seem to be the case in Italy or other European countries.