I'm copying DTC's thread. So what??
In comparison with Rain Dance, Sunny Day teams have historically been of lesser importance. For example, Swift Swim is administered to 33 Pokemon, and only three of them are not Water-type (Armaldo and its prevo, and Beartic). The vast majority of SS abusers have their own STAB moves amplified even further under the rain, making them that much harder to handle under their own weather. On the other hand, there are actually 35 Pokemon with Chlorophyll, but none of them have quite the advantage that the Water-type SS abusers have: they're all Grass-types, so the boost for Fire-type moves essentially means nothing for most of them outside of Hidden Power. The introduction of Stealth Rock in Gen IV also doomed many potential Fire-type Sun abusers, as the burden of constantly spinning away Stealth Rock dissuaded many people who might've tried making a Sunny Day-based team. Rain Dance also has a much better claim to type coverage overall: Water-, Flying-, and Electric-type attacks are common on nearly all Rain teams, while the Fire- and Grass-types on Sun teams traditionally have really limited movepools, meaning they often have to rely on Hidden Power (I mean seriously look at Lilligant's moveset).
But with Sawsbuck and Charizard dropping to NU, nearly all of the best Sun abusers in the game reside in our tier - perhaps the underdog Sun teams will finally be seen as the top dog down here? If anything, it's generally much harder to handle Sun down here: the brute force of Specs Charizard will shred through nearly any team, and then the Chlorophyll abusers can clean house afterwards. But yes, some of the best abusers of Sun to follow!
With an excellent base 100 Speed, Charizard doesn't even need Chlorophyll to outpace the majority of the metagame. Add to that the immense power that Solar Power brings (as well as STAB and the boost to Fire-type moves from Sun), and it becomes apparent that Charizard's Fire Blast is clearly the wrecking ball of choice for Sun teams. Whether its using a Choice Specs set or a more conservative set with perhaps Life Orb, Leftovers, or Expert Belt, Charizard is a force to be reckoned with inside and outside of Sun.
While not necessarily forced to use Chlorophyll, Sawsbuck is the fastest abuser of Chlorophyll available in NU. This allows it to outpace even the fastest Choice Scarf users in NU, and can be a failsafe to many teams that rely on revenge killing the slower Sun sweepers. Sawsbuck is an excellent Pokemon in Sun or out of it, and can function as a powerful wallbreaker for the heavily specially-oriented Sun sweepers. It's also fairly self-sufficient thanks to Horn Leech, which is basically a physical Giga Drain. Also the summer form is by far the best, no questions asked. :)
Exeggutor is often overlooked because of its pitiful Speed, but is easily one of the best Chlorophyll users. I mean, just look at that massive base 125 Special Attack, and STAB Leaf Storm/Psychic options. It's also got Sleep Powder and Sunny Day itself - if, say, the Sun were about to burn out the next turn, Eggy could just put an opposing Pokemon out cold and set up the Sun once again, for more fun to be had. There are plenty of other great Chlorophyll abusers down here too; Victreebel and Shiftry are probably the most notable of the rest.
I really don't want to go any more tl;dr than DTC did (because, I mean, DTC sucks) so I'll just drop a few discussion questions here:
Don't feel limited to these topics of discussion, either! Feel free to describe your experiences with Sunny Day and discuss the best way to go about it. I'm not particularly a great weather player anyway, so I've got a lot to learn about it. GOGOGO DISCUSS

In comparison with Rain Dance, Sunny Day teams have historically been of lesser importance. For example, Swift Swim is administered to 33 Pokemon, and only three of them are not Water-type (Armaldo and its prevo, and Beartic). The vast majority of SS abusers have their own STAB moves amplified even further under the rain, making them that much harder to handle under their own weather. On the other hand, there are actually 35 Pokemon with Chlorophyll, but none of them have quite the advantage that the Water-type SS abusers have: they're all Grass-types, so the boost for Fire-type moves essentially means nothing for most of them outside of Hidden Power. The introduction of Stealth Rock in Gen IV also doomed many potential Fire-type Sun abusers, as the burden of constantly spinning away Stealth Rock dissuaded many people who might've tried making a Sunny Day-based team. Rain Dance also has a much better claim to type coverage overall: Water-, Flying-, and Electric-type attacks are common on nearly all Rain teams, while the Fire- and Grass-types on Sun teams traditionally have really limited movepools, meaning they often have to rely on Hidden Power (I mean seriously look at Lilligant's moveset).
But with Sawsbuck and Charizard dropping to NU, nearly all of the best Sun abusers in the game reside in our tier - perhaps the underdog Sun teams will finally be seen as the top dog down here? If anything, it's generally much harder to handle Sun down here: the brute force of Specs Charizard will shred through nearly any team, and then the Chlorophyll abusers can clean house afterwards. But yes, some of the best abusers of Sun to follow!

With an excellent base 100 Speed, Charizard doesn't even need Chlorophyll to outpace the majority of the metagame. Add to that the immense power that Solar Power brings (as well as STAB and the boost to Fire-type moves from Sun), and it becomes apparent that Charizard's Fire Blast is clearly the wrecking ball of choice for Sun teams. Whether its using a Choice Specs set or a more conservative set with perhaps Life Orb, Leftovers, or Expert Belt, Charizard is a force to be reckoned with inside and outside of Sun.

While not necessarily forced to use Chlorophyll, Sawsbuck is the fastest abuser of Chlorophyll available in NU. This allows it to outpace even the fastest Choice Scarf users in NU, and can be a failsafe to many teams that rely on revenge killing the slower Sun sweepers. Sawsbuck is an excellent Pokemon in Sun or out of it, and can function as a powerful wallbreaker for the heavily specially-oriented Sun sweepers. It's also fairly self-sufficient thanks to Horn Leech, which is basically a physical Giga Drain. Also the summer form is by far the best, no questions asked. :)

Exeggutor is often overlooked because of its pitiful Speed, but is easily one of the best Chlorophyll users. I mean, just look at that massive base 125 Special Attack, and STAB Leaf Storm/Psychic options. It's also got Sleep Powder and Sunny Day itself - if, say, the Sun were about to burn out the next turn, Eggy could just put an opposing Pokemon out cold and set up the Sun once again, for more fun to be had. There are plenty of other great Chlorophyll abusers down here too; Victreebel and Shiftry are probably the most notable of the rest.
I really don't want to go any more tl;dr than DTC did (because, I mean, DTC sucks) so I'll just drop a few discussion questions here:
- Do discuss who the best abusers of Sun are - who's the best, who's the worst, and who is the most underestimated? Is Chlorophyll the way to go? Or should we be more centered on Fire-types like Charizard and Magmortar?
- Do you use a Rapid Spinner? Do we need to use Rapid Spinners with Sun teams? Is it a necessity?
- Who is the best user of Sunny Day? Should the Sunny Day setter be reliable and able to set the Sun again and again (Miltank,
Mesprit, Gardevoir), or be a one-time opportunity (Volbeat)? - Is a defensive Sunny Day team a possibility? Is it worth using Sunny Day for a defensive team, or are those moveslots better filled by other moves?
- When using a Sun team, what's the best way to deal with opposing Rain teams? Sun teams?
- How do you deal with Sun when you aren't using it? What are the best checks to the Sun abusers? Who can revenge kill them, if walling them is not an option?
Don't feel limited to these topics of discussion, either! Feel free to describe your experiences with Sunny Day and discuss the best way to go about it. I'm not particularly a great weather player anyway, so I've got a lot to learn about it. GOGOGO DISCUSS