Lately, I have been feeling forced to run a TTar to counter other weather teams, but I have been wondering, how is it to face a weather a team using a team that doesnt have any weather? Do you find it challenging to the point that you can't win?
I run non weather and have an avid dislike for weather. I usually fare well against weather though.
Sand - Take Ttar out to help a lot. My Ttar counter can OHKO ttar and isn't expected to, so I usually get a free kill. Excadrill is a pain to my team if I don't get sand down, but half my team can survive one hit from Excadrill and possibly KO back. Also, I run a hail user, to use hail when their starter is dead, to shut down weather. Choice Scarf Terrakion is a pain in the ass, but then again it's a pain in the ass out of sand anyway. Scarf Landorus is a pain in and out of sand, but more in sand, and a knock off lets my sweepers kill it.
Rain - Very irritating. My Rotom OHKO's in most cases with Leaf Storm, and then I can shut down the rain with hail. Toxicroak is a pain in the ass in rain, but a well used trick all but shuts it down. (if it comes in on your ghost after it's tricked it definately has sucker punch) Thundurus is said to be a rain abuser, but he's very frail, killed easily. Rain teams are quite irritating, but after toad dies i shut them down.
Sun - Possibly very powerful, but at the same time I can sweep them clean. My team doesnt have to even stop sun, but it's probably recommended in most cases. But if not, weather ball is 150 BP that murders chlorophyll sweepers in sun, and after I take heatran down, a Flash Fire Sun boosted Chandelure can 2HKO most pokemon that even resist it, and clean OHKO neutral mons, hence sweeping sun teams with their own firepower. If I fail to stop them, they can become very powerful and difficult to stop.
Hail - Lol. Ice types are nuked by Chandelure, and my froslass gets free hail evasion hax to wreak havoc as he wishes. My party has strong walls too that resist hail, blizspam won't break through my spec wall.
Overall, I'd say moderate difficulty since nearly every team uses weather -_-, and I have to constantly deal with it. If weather stopped being on every other team, I might be able to get rid of my hail froslass for a more powerful or versatile sweeper, but I can deal with weather relatively well as it is. Some can be very annoying, such as someone that uses sun well, or rain used well that I don't stop, but it's of average difficulty.