Route brief · BOS → WAS
Boston → Washington
$241
−9% vs typical
seasonal median $265 · difference $24
Sep 27 – Sep 28 · 1 night
United1 stop
- Usual monthly lows
- $242–$264
- Board rank
- Stronger than 17%
- Route sample
- 4 observed months
Cached fare — the booking search re-prices live before you pay.
Destination briefWASWashingtonFree museums by the dozen, and three airports competing hard enough to keep transatlantic fares honest.Best windowApr–May · Sep–OctAirportsDulles (IAD) · Reagan National (DCA) · Baltimore (BWI)All routes into WashingtonWhen this route gets cheap.
Cached-fare history: across 4 months, Sep is the cheapest for BOS → WAS. Best time to be there: Apr–May · Sep–Oct.
Fares bottom out in September around $241 and peak in August near $316 — a $75 spread across the 4 months we track. The cheapest itinerary we are tracking makes one stop and takes about 3 hours outbound, on a 1-night trip — ticketed under United, which on a connecting fare need not operate every leg.
The 4 days we hold a cached fare for
Tap a date → live search
The median cached fare across this calendar is 4% lower than when tracking began on Aug 8 — $280 then versus $269 now, across 5 recorded snapshots. This is a calendar-level trend, so an individual deal above can be lower. The lowest single day we have seen here is $112, on Sep 15.
These are the only days we have a cached price for on this route so far — not the only days it flies. The search above covers any date.
Cheapest in Sep · around $241
9% below the $265 typical fare
Cheapest round-trip fare found per month · Boston → Washington · cached-price history
Route facts
- Airports
- Logan (BOS) ↔ Dulles (IAD) · Reagan National (DCA) · Baltimore (BWI)
- Flight time
- ~3 hours outbound
- Distance
- ~634 km each way
- Typical price
- $265 round-trip (seasonal median)
- Airlines on the board
- United
- Itineraries
- Connections on current fares
- Best months to visit
- Apr–May · Sep–Oct
BOS → WAS, answered.
Is $241 a good price for Boston to Washington?
Only slightly. The seasonal median is around $265 round-trip and this fare is 9% under it, about $24. We do not call a drop notable until 20%, so this is an ordinary price for the route rather than a reason to hurry.
What is the cheapest month to fly from Boston to Washington?
Across 4 months of cached-fare history, Sep comes out cheapest on this route. The best months to actually be in Washington are Apr–May · Sep–Oct — when those overlap, that's your window.
How far in advance should I book BOS → Washington?
We do not publish a number for this, because we cannot measure it yet. Answering it honestly means watching the same departure date on this route over many weeks as it approaches, and that archive is still filling up — so any "book N days ahead" figure here would be borrowed from somewhere else rather than measured. What we can measure is which month is cheap: across 4 months of cached fares, Sep comes out lowest on this route. See /guides/what-moves-a-flight-price/ for what does move a fare.
Are there nonstop flights from Boston to Washington?
The current cheapest fares involve a connection, ticketed under United. Nonstop options exist on many dates at higher prices — check the live search for your exact dates.
Are these prices guaranteed?
No — these are cached fares found on real searches (this one on September 1). Airlines reprice constantly, so the booking search re-checks the live price before you pay. Fresher finds are far more likely to still be available.
Next step
Sleeping in Washington?
Lock the flight first — then compare stays for Sep 27 – Sep 28 · 1 night.
Browse hotels ↗
Missed it?
Cached fares expire. This route has a feed of its own — follow it and the next BOS → WAS drop reaches you as soon as we find it.
Follow BOS → WAS