PoolWindow

Pool season · Tennessee

Franklin Pool Season: the Year on One Bar

Last updated: July 25, 2026 · dates · water temp

Franklin's whole pool calendar, condensed: when the water warms, when it cools, and where today falls between those edges. Use the opening guide and closing guide for the step-by-step work; keep this page for the dates.

Courtyard swimming pool at dawn in a temperate climateFranklin, TN — 135 swim days a year
J F M A M J J A S O N D today (build date)

off-season opening window swim season closing window

The bar compresses Franklin's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the April 2–April 23 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends October 24. Wherever the today marker sits, the nearest color change is your next appointment.

The Franklin pool calendar

April 9open by
October 24close by
13580°F+ days
80°Fwater peak

Opening — target April 9

Open by April 9 — a two-week head start on the April 23 crossing keeps startup chemistry small and beats the local service rush.

Full opening guide

Closing — deadline October 24

Hold the cover until October 14, then winterize by October 24, a week ahead of the October 31 freeze normal. Late and cold beats early and warm.

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 Franklin water runs about 39°F at its winter floor and 80°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 Franklin's own normals — the shape of a typical year, not a forecast. The widget above shows where the current year actually sits.

30°40°50°60°70°80°90°JanFebMarAprMayJunJulAugSepOctNovDec65° algae zone58° swimmable startopen Apr 9close Oct 2480°F peak39°F floor
Site-model seasonal water estimates for an unheated in-ground pool near Franklin Sewage Plt — ±5°F, see methodology.
JanFebMarAprMayJunJulAugSepOctNovDec
40°40°46°55°64°72°79°79°76°66°54°45°

Warmest water typically July–August (peaking near 80°F); heaters and covers shift any month up.

Every station tells its own story: compare this curve with Cleveland's pool season and Jackson's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Tennessee season index.

Franklin pool season FAQ

When should I open my pool in Franklin, TN?

Target April 9. That date backs off two weeks from the day Franklin's 7-day mean temperature reaches 61°F, so you start up in cold, algae-resistant water. Work the full checklist in the Franklin opening guide.

When should I close my pool in Franklin?

The closing deadline is October 24 — late enough that the water has cooled out of the algae zone, early enough to beat Franklin's first-freeze normal by about a week. See the Franklin closing guide for the winterizing steps.

How long is the swim season in Franklin?

Franklin averages 135 days a year with normal highs of 80°F or better — right on the statewide median. The Tennessee season index ranks all 14 covered cities by the same metric.

How warm does pool water get in Franklin?

An unheated pool near Franklin typically peaks around 80°F in high summer and bottoms out near 39°F in winter, spending roughly 2 months at or above the 78°F comfort line most swimmers prefer. The month-by-month curve above shows the whole cycle; the methodology page explains the ±5°F error bars.

Data: NOAA 1991–2020 climate normals via Franklin Sewage Plt (1.8 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.