Pool season · Virginia
Portsmouth Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
This is the one-page view of Portsmouth'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.
Portsmouth, VA — 105 swim days a yearThe bar compresses Portsmouth's whole pool year into one lane rope: gray floats for the off-season, hollow teal for the March 31–April 21 opening window, solid teal for swim weeks, hollow amber for the closing stretch that ends October 28. Wherever the today marker sits, the nearest color change is your next appointment.
The Portsmouth pool calendar
Opening — target April 7
Open by April 7 — a two-week head start on the April 21 crossing keeps startup chemistry small and beats the local service rush.
Closing — deadline October 28
Hold the cover until October 18, then winterize by October 28, a week ahead of the November 16 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
This is Portsmouth's typical-year water curve: the same EWMA model as the live widget, run on the 1991–2020 normals instead of this week's weather.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 42° | 41° | 46° | 55° | 64° | 71° | 78° | 79° | 75° | 67° | 56° | 47° |
Warmest water typically July–August (peaking near 79°F); heaters and covers shift any month up.
Every station tells its own story: compare this curve with Norfolk's pool season and Richmond's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Virginia season index.
Portsmouth pool season FAQ
When should I open my pool in Portsmouth, VA?
The site model recommends opening by April 7 — about two weeks before Portsmouth's 7-day mean temperature crosses 61°F, while the water is still too cold for algae. The step-by-step sequence is in the Portsmouth opening guide.
When should I close my pool in Portsmouth?
Winterize by October 28. The model holds the deadline a week ahead of Portsmouth's NOAA 50% first-freeze date, so the plumbing is protected before the first hard night. The full sequence is in the Portsmouth closing guide.
How long is the swim season in Portsmouth?
Portsmouth averages 105 days a year with normal highs of 80°F or better — right on the statewide median. The Virginia season index ranks all 16 covered cities by the same metric.
How warm does pool water get in Portsmouth?
An unheated pool near Portsmouth typically peaks around 79°F in high summer and bottoms out near 40°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.
Email me when Portsmouth hits the closing window
Data: NOAA 1991–2020 climate normals via Norfolk S (7.1 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.