Open on time.
Close on time.
Dose right in between.
Pool season is a local date — six weeks apart between Minneapolis and Dallas. PoolDates reads 1991–2020 NOAA temperature records for 147 US cities and turns them into opening days, closing days, and every dose your water needs along the way.
Try “Austin” or “55401” — or spin the globe and tap a city.
All tools
Pool Season Lookup
Enter your ZIP — see when pools in your town usually open, when they close, and how long the season runs.
🧪Chemical Dosing Calculator
Pool volume + test readings → exact doses of chlorine, acid, baking soda, stabilizer, and salt, in cups and pounds.
📏Pool Volume Calculator
Rectangle, round, oval, or kidney — get gallons from your pool’s shape and depth, ready for every dose.
🔥Heater Cost & Sizing Calculator
Gas vs heat pump vs electric: the BTUs you need and what each degree — and each month — will cost.
⏱️Pump Runtime Calculator
How many hours your pump actually needs to run for a full turnover, and what those hours cost on your power bill.
⚖️Water Balance (LSI) Calculator
The saturation index behind the test-strip colors: is your water corrosive, balanced, or scale-forming?
Season dates, state by state
When to open, when to close, and how long the season runs — for cities in every state, from 1991–2020 NOAA records. Browse all cities →
Coming soon
Winterizing ChecklistSoon
A closing-day walkthrough matched to your climate — what to do, in order, before the cover goes on.
New tools ship regularly
Get a short email when a new tool goes live. No spam, unsubscribe anytime.