Summer

Clean or replace furnace filter as needed.
Check carbon monoxide detectors and smoke detectors.
Recharge fire extinguisher.
Clean range hood filter.
Air out damp basements on dry days or use a dehumidifier.
Check and repair caulking and grout in bath and shower tiles.
Inspect basement and/or crawl space for seepage and leakage.
Check around the exterior of the house to make sure there are no low areas that can pool water and cause basement damage.
Service air conditioning unit and make up air unit.
Re-caulk windows and doors.
Check gutters and downspouts and clean if needed
Trim trees and shrubs.
Mow grass slightly higher during the hot weeks of summer.
Water grass at least one inch per week, depending on soil.