Unless you have disabled summer while Customizing Your Seasonssummer will be the first season you encounter when loading up a new neighborhood after installing Seasons or if you create a new neighborhood. For the most part, summer is a good "neutral" season that doesn't change the way you've been playing The Sims 3.
For all intents and purposes, you can say that your neighborhoods prior to the Seasons expansion were all in a perpetual, cool summer. The symbol itself shows what the current season is as well. The sun represents summer, and given that we're going with default settings, we won't see fall for a week.
It's 68 degrees, but only 8am, so the temperature is sure to rise. Pyro enjoys warm weather but wants to make sure he's dressed for it, so he heads to his modestly large television and interacts with it. A special "Check Weather" command lets him tune into the weather channel and check out the six-day forecast. Looks like it's going to be a hot few days!
The rain on Monday will help keep things pleasant, but Tuesday is going to be pretty nasty. Pyro still has the Bookworm and Couch Potato traits though, so he'll be happy as always with his butt planted on the sofa while soaking up the air conditioning.
Even though the forecast can be inaccurate just like reality, Pyro decides that he doesn't want to take any chances. Remember that all homes are automatically and retroactively climate-controlled, and do not need any additional objects purchased. As long as a Sim is within four walls under a roof, his temperature will always stabalize with enough time.
Becki will have to stay indoors as well. Being a SimBotshe'll start short-circuiting if she's rained on for too long.
As long as she moves quickly such as the short trip outside to and from the Sims 3 online dating without seasons in the sunshe'll be all right. Pete however enjoys the outdoors and continues to workout in his sandy training area outside the towers. It isn't long before he draws a neutral moodlet called "Getting Warm" due to his increasing temperature, soon followed by a "Sweating Profusely" debuff as he starts frying.
Note that by the time he got the second debuff, the temperature had already peaked and cooled back down to a nice 72 degrees. As you can see, the temperature generated from activities is also factored into whether Sims draw those debuffs. Pete continued to exercise well past when he should have, which is why he drew the debuff despite the cooling weather.
Pete eventually stops exercising on his own despite no commands to the contrary, and despite the fact that he's not fatigued yet.
A Sim's self-preservation instincts will often keep them from suffering any problems relating to the weather, but there is a chance they may stay out longer than they should. In a worse-case scenario, staying out too long will cause the Sim to suffer sunburn, or even spontaneously combust!
It's pretty tough to see one of these scenarios happen, especially if you have weather active, but you'll still want to be wary if your Sims are outdoors for a while.
The summer festival, like all festivals, is available from the first day summer starts, though Leisure Day or at least a day off work is probably the best time to visit it since you'll be able to spend all day there. While Pete and Becki continue to do household things, Pyro decides he's has a long couple days of doing nothing productive, so he heads down to the lot.
Being that he lives in Riverview, the festival doesn't take place in a park, but rather in a previously abandoned warehouse. Thankfully, all the attractions are still present. Pyro heads upstairs in the warehouse and examines one of the few unique objects for summer: Items like this are buyable in Buy Mode even out of season, so Pyro decides to get one once he gets home.
Still, he doesn't quite need to yet. In order to earn festival tickets, Pyro merely has to do any activity at the festival.
Festival tickets are universal, not per-season, so Pyro could save them up for now and redeem them in a different season. Also, they're transferable, so a whole family could pool their tickets together by using the "Give Gift" social interaction. After eating entirely too many nachos, Pyro heads back downstairs as others start to populate the lot.
There's an eating contest outside, so Pyro joins it to earn some festival tickets.
After that, he takes a greeting card photo in the photo booth, which can be posted to your Sims 3 wall as well as Facebook wall or Twitter feed if you have those connected to your game. He also gets his face painted like a lunatic and skates around the roller rink, all of which earns him festival tickets!
There are still more activities outside: He can also play a little one-on-one soccer at the nearby soccer goal. Winning any event, such as a soccer shootout or the eating competition, yields more festival tickets than a loss, but he'll get a few just for participating.