Ok, so this thread is mostly just for DM's when planning...I've created/enshrined a lot of the seasonal chages, so here is a summary of what we have so far:

Summer:  Summers tend to be warm, but not overly so.  The Bandit Summer [The Message] was a very hot summer.  Rivers during summer run easy, and the ford(s) are fully open to wagon travel.  Summer begins in late June and streches to later September.  Bandit activity reaches it's peak in summer.

Autumn: It has not been determined how autumn affects Rianardu.

Winter: It has not been determined how winter affects Rianardu.

Spring:  Fords open with the spring melt.  Thunderstorns are common.  Fording rivers can be difficult.  Bandit activity in the Greenwealde starts to rise as more people make their way along the highway.  Flash Flood (jocalops (spelling?)) are an occational occurence.

FYI:  This is why it is hard to get supplies to Khal.  The King's Highway is only really open  a few months out of the year, and those months signal an increase in bandit activity.

Yaay this fets fairly well. I have determined slightly different climates for the far north of our main island, but they are on a sheet that Opal has so I will post them later. I would say where Gold Bar is isnt cold enough for constant snow, but as you increase in elevation it becomes a constant thing (definatly Kahl woiuld be consatntly under snow during the winter months IMO.

So the lower greenwealde is liek seattle in fall/winter.  Rain and some snowfalls.  Should we call the snowline 3000' in the winter?  that is most of the upper greenwealde (explains why bandits don't come out much)  Also, I imagine that the Lyona does get snow, including Orlean, and more of it than the forest. (but that's just my 2 coppers).

as an update to the northlands (hint hint nudge nudge): I have 3 main temperature bands. First is what i called "warm tundra", which I simplified to above freezing spring/summer/fall are all above freezing. Next is "Tundra", which is frozen 3 out of 4 seasons of the year. Last but not least is "Frozen", which never thaws.

Of my cities that I made, Erudite (southern most Aldori city) is outside of my temperture bands, which means it follows temperature rules for the Lyona Plains. New Westhaven and Solomount are both in the Warm Tundra band. Icelock is far enough north that it falls into the Frozen temperature band.