Pool season · Massachusetts
Lawrence Pool Season: the Year on One Bar
Last updated: July 25, 2026 · dates · water temp
This is the one-page view of Lawrence'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.
Lawrence, MA — 66 swim days a yearEach dot on the bar is one week of Lawrence's typical year, colored by what the model says that week is for: gray weeks are off-season, hollow teal marks the opening window (May 3–May 24), solid teal is swim season, and hollow amber is the closing window ending October 6. The black marker is today — its position against the colors is the entire executive summary.
The Lawrence pool calendar
Opening — target May 10
Target May 10; the practical window runs May 3–May 24, and the 7-day mean crosses the 61°F threshold around May 24. Cold-water starts are the cheap ones.
Closing — deadline October 6
Hold the cover until September 26, then winterize by October 6, a week ahead of the October 28 freeze normal. Late and cold beats early and warm.
Estimated water temperature by month
This is Lawrence'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 |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 30° | 28° | 33° | 44° | 55° | 64° | 72° | 74° | 70° | 59° | 48° | 38° |
The curve peaks near 74°F — comfortable-water months here usually involve a heater or a solar cover.
Every station tells its own story: compare this curve with Fall River's pool season and Leominster's — neighboring normals stations can shift the windows by a week or more. The full ranking lives on the Massachusetts season index.
Lawrence pool season FAQ
When should I open my pool in Lawrence, MA?
The site model recommends opening by May 10 — about two weeks before Lawrence'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 Lawrence opening guide.
When should I close my pool in Lawrence?
Winterize by October 6. The model holds the deadline a week ahead of Lawrence's NOAA 50% first-freeze date, so the plumbing is protected before the first hard night. The full sequence is in the Lawrence closing guide.
How long is the swim season in Lawrence?
Lawrence averages 66 days a year with normal highs of 80°F or better — right on the statewide median. The Massachusetts season index ranks all 14 covered cities by the same metric.
How warm does pool water get in Lawrence?
An unheated pool near Lawrence typically peaks around 74°F in high summer and bottoms out near 27°F in winter, never quite reaching the 78°F comfort line without a heater or solar cover. The month-by-month curve above shows the whole cycle; the methodology page explains the ±5°F error bars.
Email me when Lawrence hits the closing window
Data: NOAA 1991–2020 climate normals via Lawrence (0.2 mi); live outlook by Open-Meteo. Attribution: sources · assumptions: methodology.