Sorry, only Samsung apps and features have complications for the watch face. Some more informative faces allow for the addition of Google Wallet, WhatsApp and Spotify as complications. I'm not sure what the default refresh interval is for Samsung Weather, it's either every 15 minutes or half hour. There does not seem to be an option to select an interval. I do agree, though, it's rather stup-id to have to scroll all the way down to do a manual refresh. I can swear I used to just tap the complication or the tile and the refresh arrow was right next to the temp.
If you go the Play store and search for weather apps, when your search results come up, on the upper left in the blue box where it says "this device", tap it and switch it to look for apps for your watch. Adding the app to the watch itself may then allow for either a complication or a tile widget.
