May is the month everything is still easy. The weather is mild, the contractors aren't slammed yet, and every problem you find now is a small one. Wait until July and the same list turns into a sweaty, expensive scramble while every HVAC company in town is booked two weeks out. I treat the third weekend of May as my annual "get ahead of summer" morning, and it has saved me more than one bad week.
This is the short version — the things that actually matter, none of which need a pro. Budget a Saturday morning, or skip to the 20-minute version at the bottom if that's all you've got.
1. Get the AC Ready Before You Need It
The single highest-leverage thing on this list. Don't wait for the first 90-degree day to discover the system doesn't cool — that's exactly when you can't get a technician. Run the full pre-season routine now: fresh filter, clear the outdoor condenser, flush the condensate line, and run a test cycle. The whole thing is laid out step by step in our pre-summer AC tune-up, and if you do nothing else, at least change the HVAC filter — a clogged one can freeze the coil on the first hot day.
2. Clean the Gutters One More Time
Spring drops a second round of debris — seed pods, maple helicopters, and the last of the catkins — right after most people did their "spring" gutter clean. Summer storms are heavier and faster than spring rain, and a clogged gutter sends that water straight down your foundation or behind the fascia. Scoop them out, flush with a hose, and confirm the downspouts actually run. A cheap gutter scoop makes this a ten-minute job instead of a knuckle-scraping one.
3. Inspect the Deck and Exterior Wood
Winter is hard on outdoor wood, and you want to find soft boards before someone finds them with a foot. Walk the deck and press a screwdriver into anything that looks dark or feels spongy near the ledger board, stair stringers, and railing posts. Tighten loose railings now. If the wood is graying or water no longer beads on it, this is the month to clean and reseal — early enough that it cures before the deck gets daily summer use.
4. Test Irrigation and Dial In the Lawn
Run every irrigation zone and watch it — look for heads spraying the sidewalk, geysers from a cracked head, or dry zones that never get water. If you're still hand-dragging a hose around the garden, May is the time to fix that for good with a drip irrigation system; it pays for itself in one dry August. While you're outside, give the lawn its early-summer reset per the spring lawn care guide so it goes into the heat strong instead of stressed.
Pro Tip
Take a phone photo of your irrigation timer settings before you change anything. If a zone misbehaves later you'll know exactly what "normal" looked like — and you won't be reprogramming the whole thing from memory in August.
5. Seal the Gaps
Every gap you can see is a gap conditioned air escapes through all summer. Walk the exterior and check the caulk around windows, doors, and where pipes or wires enter the house. Cracked, shrunken, or missing beads get redone — it's a cheap afternoon that quietly lowers the cooling bill. The how and the right product for each spot is in our guide to caulking like a pro.
6. A Quick Interior Round
Ten minutes inside catches the slow, expensive stuff:
- Test every smoke and CO detector and swap any battery you can't remember replacing.
- Check under sinks and around the water heater for damp spots or mineral crust — early signs of a slow leak.
- Fix any faucet that drips. It wastes more water than you'd think and the repair is usually under $10 — see how to fix a leaky faucet.
- Clean the dryer's lint trap housing and check that the outside vent flap actually opens. Lint plus heat is how dryer fires start.
The 20-Minute Version
No Saturday to spare? Do exactly three things and you've covered most of the risk: change the HVAC filter, scoop and flush the gutters, and run one full irrigation cycle while you watch. Everything else can wait a week. The goal isn't a perfect house — it's catching the one small problem now instead of the one big one in July.
Once May's list is done, you're set up for the heavier summer home maintenance checklist, and if you want to turn this into actual money saved, the DIY energy audit is the natural next hour. Future you, in a cool and dry house while the neighbor waits on a service call, will be glad you spent the morning.