Before tossing open those windows, check your screens. Some may need replacement or patching to keep out pesky insects. You also want to check the seals around exterior doors, otherwise ants and other insects may make their way into the home.
We spend much of our summer gardening. I always clean the entryway rugs at the start of the year, otherwise our floor quickly becomes a morass of mud and grass clippings. Keeping a broom and dust pan near each door further helps remind me to sweep regularly so the mess isn't tracked all over the house.
Who has time for cleaning when the sun is shining and birds are singing? I know many people who keep a clean home that let it all fall apart when the weather gets nice. Instead, set aside an hour a week to attend to basic chores. I prefer to do it early in the morning on a weekday before the day really gets started so I don't have to give up my weekend. Doing a quick tidying up each evening before bed prevents messes from becoming too big.
Finally, keep your outdoor living spaces welcoming. Wipe down patio tables or furniture daily so they don't become sticky and attract bugs. Sweep walkways and paved areas regularly. Also, keep a covered trashcan near outdoor living areas to make cleanup automatic.