As someone who helps salespeople grow revenues, I love the summer season and I also dislike it almost equally. From a selling standpoint, this can be one of the BEST times to catch up or even get ahead of your competition - since many of us mentally slow down. Especially in areas where there are more defined seasons - like New England - I noticed when I lived there that suddenly the focus on weekend getaways, weddings to attend, and trips to plan gained momentum as the customers and prospects took a back seat.
I LOVE Summer because my motivated clients make progress and gain revenues by working a specific plan and by working hard during the next few months. They see great progress, and that is very rewarding to me.
I DESPISE Summer because sometimes other clients I am working with mentally kick back and figure it is always a bad time to contact prospects. They LOSE ground, get de-motivated.
Living in the Pacific NW, we have very mild weather year-round, so many of us here just keep doing what we are doing. if we are motivated, we stay motivated, and if we are slackers, we stay slackers. The extra sunshine doesn't change that much.