KEY COLONY
Homes for Sale in Marathon, FL
True comps, carrying-cost math, and listings before the portals.
Market Heat
Key Colony sits within Marathon in Monroe County — the Florida Keys — and the current median price of $475,000 reflects the premium that waterfront-adjacent island inventory commands in this market. Pricing here is condition-driven and spread wide: the difference between a storm-hardened, elevated home and an unrenovated one can be dramatic, so the median tells you where the center of gravity is, not where any individual property will land.
The market is moving fast. A median of 11 days on market signals that well-priced listings are not sitting, and that buyers who need extended decision cycles are at a structural disadvantage. The market heat score of 49 suggests equilibrium rather than a full seller's market, but the velocity of closings indicates real demand — not speculative froth.
KEY COLONY right now
🔴 Off the recent peak. The trailing-12-month median ($475K) is down 39.1% from the prior 12 months ($780K) and up 70% since 2012. With about a dozen sales a year, a single closing can swing this number, so read the level and the decade, not one year's move.Momentum Research, record-level floridakeys closed sales, 12-month windows ending July 27. Confidence: Medium (7 and 9 sales in the two windows).
What's unique here: the median sale price is about 50% below the typical Monroe County sale ($475K vs $950K, trailing 12 months, floridakeys records).
Jump to: Price history & scorecard · Homes for sale · Schools · FAQ
Updated July 27, 2026 · Live data: floridakeys, refreshed twice daily · MLS facts carry their source; interpretation lines are Momentum Research · Data sources & freshness
The 60-Second Overview
KEY COLONY market snapshot (as of July 27, 2026): the median sale price is about $475K, and a median 11 days on market for closed sales. The trailing-12-month median is down 39% from the prior 12 months and up 70% since 2012, computed from record-level floridakeys closed sales (7 closings in the current window).
Key Colony is a small incorporated municipality within Marathon, giving it a distinct identity inside the broader Keys market; the combination of island geography, Monroe County's strict land-use controls on new development, and the limited supply those constraints create all bear directly on how this market prices and trades.
Who KEY COLONY is best for.
Best for
- Buyers with a budget anchored near the $475K median who are prepared to move decisively — the 11-day DOM leaves little room for deliberation.
- Buyers who want a Keys address within Marathon and understand that Monroe County land-use restrictions make this a supply-constrained market by design.
- Sellers with a well-maintained, elevated property who want to test genuine demand rather than sit on a listing.
Probably not for
- Buyers who require a wide selection of listings to compare over several weeks — active inventory in this municipality is thin and turns quickly.
- Buyers who cannot absorb Florida Keys insurance costs, which for coastal Monroe County properties can be substantial and are independent of purchase price.
- Anyone who would rely on the year-over-year percentage as a valuation shortcut without reviewing the underlying seven transactions — the data requires context this figure alone cannot provide.
Price History: What Homes Here Have Actually Sold For
Median sale price over the trailing 12 months ending July 27 of each year, from record-level floridakeys closed sales. Same methodology as every appreciation figure on this page: the 2026 point ($475K) IS the median in the snapshot above, and the move from 2025 ($780K) IS the -39.1% one-year change.
Windows contain 6 to 14 sales each (7 in the current window); every figure carries its sample size, and thin markets swing on single closings. Listing data provided by Florida Keys MLS, Inc. Information is deemed reliable but is not guaranteed by the MLS to be accurate. Deemed reliable but not guaranteed.
The real cost & risk here
Before the list price, the Florida math the portals skip. These are Monroe County typicals — your exact home, flood zone, and insurance quote will vary, so verify each before you offer.
Check it for your address: look up your flood zone (FEMA) · insurance by county · true-cost calculator · Monroe County scorecard.
County typicals from Momentum’s Florida housing data (Zillow & Realtor.com aggregates, Census, FRED), updated monthly; insurance modeled. Flood zone is property-specific — always confirm via FEMA.
The KEY COLONY buying strategy.
If we were buying in KEY COLONY today, this is the order of operations we would run for our clients.
Underwrite the condition first. Price the roof, HVAC, and systems honestly before judging any list price; condition swings value here more than square footage alone.
Match the home to real comps. Recent sales of similar condition and lot, not the asking price, tell you what a home is worth.
Move deliberately, not desperately. Neither side has a decisive edge, so a well-prepared, fairly-priced offer wins without overpaying.
Line up financing and inspection early. A pre-approval and an inspection plan let you act fast and negotiate from evidence.
Keep an agent in your corner. The listing agent works for the seller; we represent you and prepare a hand-built valuation before any offer in KEY COLONY.
Supply, Speed, and the Keys Premium
Monroe County's regulatory environment makes meaningful new residential supply in Key Colony essentially impossible at scale. Every transaction is a resale, and every resale competes for a finite pool of buyers who specifically want the Keys lifestyle. That structural scarcity is a permanent feature of this market, and it is the most important thing to understand before negotiating here.
The year-over-year price change of -39.1% from the prior period demands attention and an explanation before a buyer or seller draws conclusions. A reading that sharp in a low-volume market — 7 closings in the measurement window — typically reflects a shift in the mix of what sold rather than a collapse in underlying value. A single high-end or distressed outlier in a pool this small can move the median dramatically. Buyers should not interpret this figure as a buying-opportunity signal, and sellers should not panic. Both sides need a broker who can read the actual comparable transactions rather than react to a headline percentage.
The location and the amenities are priced into every listing in KEY COLONY. The deal is won or lost on condition, the comps, and the renovation math.
Momentum Buy Score.
Our proprietary 0 to 10 read across the factors that decide how a home in KEY COLONY buys, holds, and resells. Momentum Research; not an appraisal.
Momentum Intelligence Scores are our proprietary, qualitative assessment on a 0 to 10 scale, built from the record-level market data on this page. They are a framework for comparing communities, not a guarantee of future value and not advice on a specific home; unlike an automated value estimate they do not price your home, they grade the community on evidence you can inspect. Composite is the plain average of the 3 factors (3.5). Basis: Long-Term Appreciation +70% since 2012; Recent Direction -39.1% year-over-year; Pricing Power 92.2% sale-to-list. Refreshed with each data update.
Why work with Momentum here
In a market where seven closings define the measurement window and a single transaction can swing the median by double digits, data interpretation is the job — not just data retrieval. Momentum Realty brings the transactional discipline to read through mix-shift noise, price to the actual comps, and move clients through an 11-day median velocity without leaving anything on the table. The Keys are not a place to learn on the job.
KEY COLONY in 15 seconds.
HOA, CDD & Fees
- Mandatory HOA — confirm current dues
- Any club/amenity membership is billed separately
Confirm the current HOA dues, exactly what they cover, and any CDD bond or special assessment for a specific address before you offer.
Tools for a KEY COLONY buy.
Free calculators to pressure-test the real cost before you tour.
Selling here is won on condition and pricing to real comps, not an automated estimate. The right number comes from closed KEY COLONY sales matched to your home.
Price it to the comps and condition, not an automated estimate.
If you are thinking about selling in KEY COLONY, the right list price comes from recent comparable sales matched to your home's condition and location, not an automated estimate.
What is your KEY COLONY home worth?
Get a no-obligation home value based on real comparable sales in KEY COLONY, not an automated guess. Tell us about your home and we will personally prepare your numbers and a pricing strategy. No obligation, no spam.
See homes for sale in KEY COLONY on the map →
Frequently Asked Questions
What is the median home price in KEY COLONY?
How long do homes in KEY COLONY take to sell?
Have KEY COLONY home prices gone up?
Who is the best real estate agent for KEY COLONY?
How do I find a top Marathon real estate agent who knows KEY COLONY?
Can Momentum Realty connect me with an agent for KEY COLONY?
Should you buy in KEY COLONY?
An honest fit check. We will tell you when it is not your community.
Data sources & freshness
| Community market stats | floridakeys closed sales, 12-month windows ending July 27, 2026 |
| Historical depth | Closed-sale records back to 2006 (171 transactions analyzed) |
Verify the primary sources yourself: Florida DOR · U.S. Census · FEMA flood maps · Citizens Property Insurance.
Momentum Research figures are our own analysis of floridakeys records; MLS data is deemed reliable but not guaranteed. Methodology: how Momentum market scores are computed. Market metrics describe homes for sale and recent sales, not residents.
Own a home here?
You just read the data. Now see what your home is worth.
The numbers on this page move markets in the aggregate. The number that matters to you is what a buyer pays for your address. Momentum sells for 1.25% above the floridakeys member average and 8 days faster, and we’ll price yours against live your area comps.
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More Marathon & The Florida Keys & Monroe County guides
Compare before you commit - every guide covers pricing, HOA/CDD, insurance posture, and fit. Browse all of The Florida Keys & Monroe County or the full Neighborhood Finder.