23 Answers

Longer hours of daylight and more time at the pool.  The flowers blooming profusely and the two tomato plants actually producing fruit this year.  
I get a desire to go somewhere, ride my bike, hit golf balls.  
This afternoon I sat at an outdoor patio with a friend for 3 hours enjoying the company, sunshine, and the feeling that summer IS a heartbeat away.  The place is popular for bikers, and the sounds from the bikes means summer, too (and I'm not a biker chick at all).  

I think everyone knows where I live, here we just wait for the sun to come out, call it summer, and when the sun goes away we call it winter.

" In (AZ).Women rid'in horseback in bikinis." ;)

Out door barbeque's, the smell of freshly mowed grass and the sound of cicadas/crickets at nightfall. 

Swimming and flowers and vegetables in my garden.Not looking forward to mosquitos. Dont like extreme heat.

It's not summer yet in the uk , its been raining for the past 2 weeks, but I am in Clacton on sea today and it's sunny and warm, well about 15c thats warm for us. My idea of summer is coming out in the morning without a coat, and feeling some warmth on my head, and being able to leave the back door open. My cats like it when the summer comes they spend all day in the garden.

Exterior painting, BBQ Grills, Coolers on sale everywhere, kids are all hanging out at bars and shopping centers, Waikiki beaches are filled with tourists of all sizes.

Here in Las Vegas, the topless pools are opening up all over the place!  (Of course, I'm too cheap to go, so I just go to the regular pool at my apartment complex.)

They say in ain't summer on Cape Cod till one of the Kennedys drives up on a side walk..

GIRLS In Mini skirts Bathing suits "ME In my shorts expanding "chest Girls looking laughing .I turned to my "Wife and said they like what the see .NO she replied there "laughing at what they see .then she burst out laughing as well My "Trouser Zipper was open.  

It is still raining like mad in the shower stall of the planet.  I am waiting ... waiting waiting waiting for Mr. Golden Sun.  Then we practically live outside.

I'm a little envious, we are heading into winter, it's getting quite cool and hasn't stopped drizzling rain in 2 weeks, I don't like extremes of any season but am finding it harder to get out of bed early when it's still dark, and still raining

Syracuse, NY is the snow capital of the US. They have to truck the snow to an empty field and create huge piles. One of the years I lived there, the last of the snow was melted on July 4th ..... That signals the start of summer. That is also the reason I left.

Oh my, the dragonflies, butterflies, fireflies, ladybugs, all of the spiders, and snakes...watching the hatchlings grow, ...and being in less pain on warm sunny high barometer days!!!!!

Warm weather, flowers, bees, wasps, butterflies.

It is still raining like mad in the shower stall of the planet.  I am waiting ... waiting waiting waiting for Mr. Golden Sun.  Then we practically live outside.

Orange blossoms.  I forgot to mention the orange blossoms.  
And the strawberries.  The roadside strawberry stands. 

fish flies ( also called May flies ), June bugs around your porch light at night. ( I hate those things )  , Hearing the ding-a-ling of the ice cream truck. The kids getting out of school. The lack of school busses on the road, which makes it easier to drive anywhere.

It is still raining like mad in the shower stall of the planet.  I am waiting ... waiting waiting waiting for Mr. Golden Sun.

its hot 

In Michigan fireflies get here late June or July! I'm waiting for the first hummer who I expect any day now!  I really love summer!  The garden goodies are some of the best treats I know!

Little darling, it's been a long, cold lonely winter

Seems like years since I've seen the sun ...   (The Beatles. Kinda)

Real summer comes when my Sunflowers reach the clouds. 

Lots of festivals start up in the summer here. :)

The down side is we are plagued with humidity. :(