PoolWindow

Pool season · Delaware

Dover Pool Season: the Year on One Bar

Last updated: July 15, 2026 · dates · water temp

This is the one-page view of Dover's pool year: both model windows, the estimated water-temperature curve, and today's live position on the season bar. The detailed checklists live on the opening and closing guides; this page is the calendar you check between them.

J F M A M J J A S O N D today (build date)

off-season opening window swim season closing window

Reading it takes ten seconds: 52 dots, one per week. Solid teal is Dover's swim season; the hollow teal run before it (April 12 to May 3) is when to open; the hollow amber run after is when to close, with October 21 as the deadline; gray is the covered season. Today's marker shows where you stand in that cycle right now.

The Dover pool calendar

April 19open by
October 21close by
9980°F+ days
78°Fwater peak

Opening — target April 19

Target April 19; the practical window runs April 12–May 3, and the 7-day mean crosses the 61°F threshold around May 3. Cold-water starts are the cheap ones.

Full opening guide

Closing — deadline October 21

The window opens October 11 once water leaves the algae zone; the model deadline is October 21, a week ahead of the November 4 freeze normal.

Full closing guide

Where the water sits today

SEASONAL VIEW

Estimated unheated pool water temp (site model, ±5°F). The live estimate loads in your browser from Open-Meteo air temperatures; in a typical year Dover water runs about 36°F at its winter floor and 78°F at its summer peak.

40 45 50 55 60 65 70 75 80 85 58 open 65 algae

Estimated water temperature by month

Monthly averages of the site's water model run on Dover's own normals — the shape of a typical year, not a forecast. The widget above shows where the current year actually sits.

Site-model seasonal water estimates for an unheated in-ground pool near Dover — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
37°37°42°51°61°69°77°77°74°65°53°44°

The curve peaks near 78°F — comfortable-water months here usually involve a heater or a solar cover.

Data: NOAA 1991–2020 climate normals via Dover (1.2 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.