General Edward Lawrence Logan International to Boeing Fld/King County International BOS → BFI
2,162 nautical miles (2,487 statute miles) northwest on a straight line, true course 296°, about 311° magnetic at the departure end (variation 15W). At 120 knots that is 17 h 10 min at the quickest height in today's winds (4,500 ft, a 6-knot tailwind), arriving about 11:50 am PDT (18:50 UTC). For planning, not a briefing: the legal preflight briefing comes from Flight Service (1-800-WX-BRIEF) or the FAA's own tools. Airlines fly this pair: 1 flights in the DOT's last twelve reported months, the route's page.
The route the straight line, the warnings crossed, restrictions, pilot reports and the airports along the way · click a mark for its words
Green, blue, red and purple airport dots are the flying conditions reported there now (VFR, marginal VFR, IFR, low IFR); grey means no report. Red areas are SIGMETs, orange areas AIRMETs, hatched red areas temporary flight restrictions. Map tiles: OpenFreeMap, data © OpenStreetMap contributors.
Warnings the route crosses SIGMETs and AIRMETs whose area the line passes through or comes within 25 nm of
- AIRMET SIERRA 3E: low cloud or poor visibility (IFR conditions) (due to ceilings below 1,000 ft, visibility below 3 miles, precipitation, mist). Over the first 209 nm of the route.
- AIRMET ZULU 1C: moderate icing up to 22,000 ft. Over the first 229 nm of the route.
- AIRMET TANGO 3W: moderate turbulence above 18,000 ft from 21,000 ft to 33,000 ft. Over the first 249 nm of the route.
- AIRMET TANGO 2W: moderate turbulence below 18,000 ft up to 13,000 ft. Over the first 219 nm of the route.
- AIRMET SIERRA 4E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the route from 70 to 209 nm out.
- AIRMET SIERRA 4E: low cloud or poor visibility (IFR conditions) (due to ceilings below 1,000 ft, visibility below 3 miles, precipitation, mist). Over the route from 996 to 1245 nm out.
- AIRMET SIERRA 4E: low cloud or poor visibility (IFR conditions) (due to ceilings below 1,000 ft, visibility below 3 miles, precipitation, mist). Over the route from 1375 to 1813 nm out.
- AIRMET TANGO 4W: moderate turbulence above 18,000 ft from 18,000 ft to 36,000 ft. Over the route from 1414 to 1893 nm out.
- AIRMET ZULU 2C: moderate icing up to 16,000 ft. Over the route from 1644 to 2032 nm out.
- AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the route from 1763 to 1893 nm out.
- AIRMET TANGO 1W: moderate turbulence above 18,000 ft from 18,000 ft to 39,000 ft. Over the last 179 nm of the route.
A SIGMET warns of weather hazardous to all aircraft; an AIRMET of weather that matters to small aircraft and to flying without instruments. "From 60 to 180 nm out" is measured along the route from BOS.
Pilot reports along the route within 50 nm of the line, last three hours, the serious ones first
Not fetched just now.
Winds aloft along the route, and the time en route the forecast for use 20:00–03:00 UTC · at 120 knots true airspeed
The westbound cruising heights for this course (VFR: even thousands plus 500 ft; above 18,000 ft the forecast levels), with the wind averaged along the line from the 16 forecast points nearest it (BOS, ALB, SYR, BUF, TVC, GRB, DLH, INL, GFK, MOT, GGW, GTF, GPI, GEG, YKM, SEA). A plus sign is a headwind, a minus sign a tailwind.
| Height | Average wind | Head- or tailwind | Temperature | Ground speed | Time en route | Arrival |
|---|---|---|---|---|---|---|
| 4,500 ft | 110° at 4 kt | −6 kt | 1 °C | 126 kt | 17 h 10 min | 11:50 am PDT (18:50 UTC) |
| 6,500 ft | light and variable | −2 kt | 7 °C | 122 kt | 17 h 43 min | 12:23 pm PDT (19:23 UTC) |
| 8,500 ft | 240° at 4 kt | +2 kt | 4 °C | 118 kt | 18 h 19 min | 12:59 pm PDT (19:59 UTC) |
| 10,500 ft | 240° at 7 kt | +5 kt | 1 °C | 115 kt | 18 h 48 min | 1:28 pm PDT (20:28 UTC) |
| 12,500 ft | 240° at 11 kt | +8 kt | -2 °C | 112 kt | 19 h 18 min | 1:58 pm PDT (20:58 UTC) |
| 14,500 ft | 240° at 15 kt | +11 kt | -6 °C | 109 kt | 19 h 50 min | 2:30 pm PDT (21:30 UTC) |
| 16,500 ft | 240° at 18 kt | +15 kt | -10 °C | 105 kt | 20 h 35 min | 3:15 pm PDT (22:15 UTC) |
| 18,000 ft FL180 | 250° at 21 kt | +17 kt | -13 °C | 103 kt | 20 h 59 min | 3:39 pm PDT (22:39 UTC) |
| 24,000 ft FL240 | 250° at 31 kt | +27 kt | -23 °C | 93 kt | 23 h 15 min | 5:55 pm PDT (00:55 UTC) |
| 30,000 ft FL300 | 250° at 45 kt | +39 kt | -37 °C | 81 kt | 26 h 41 min | 9:21 pm PDT (04:21 UTC) |
| 34,000 ft FL340 | 250° at 53 kt | +47 kt | -44 °C | 73 kt | 29 h 37 min | 12:17 am PDT (07:17 UTC) |
| 39,000 ft FL390 | 260° at 60 kt | +53 kt | -50 °C | 67 kt | 32 h 16 min | 2:56 am PDT (09:56 UTC) |
Based on data from the 11th at 18:00 UTC; valid on the 12th at 00:00 UTC for use 20:00 to 03:00 UTC; temperatures above 24,000 ft are below zero. Heights are above sea level; a height is left out when the forecast has no wind for it over most of the line (the ground is higher). Ground speed is the airspeed less the headwind; the time en route is for the straight line and ignores climb, descent and routing around weather.
The forecast points as issued
| Point | From | 3,000 | 6,000 | 9,000 | 12,000 | 18,000 | 24,000 | 30,000 | 34,000 | 39,000 |
|---|---|---|---|---|---|---|---|---|---|---|
| BOS | used from 0 nm out; 25 nm from the line | 160/27 | 190/23 9° | 260/20 7° | 260/32 1° | 250/48 -7° | 240/56 -17° | 240/59 -33° | 250/75 -43° | 250/94 -55° |
| ALB | used from 50 nm out; 57 nm from the line | 160/27 | 190/16 9° | 200/29 7° | 230/21 3° | 240/24 -9° | 240/43 -19° | 230/65 -33° | 240/91 -42° | 230/99 -53° |
| SYR | used from 199 nm out; 53 nm from the line | 160/17 | 200/22 10° | 250/10 6° | L/V 1° | 270/11 -11° | 220/25 -20° | 220/66 -36° | 230/89 -42° | 240/74 -51° |
| BUF | used from 299 nm out; 105 nm from the line | 170/19 | L/V 10° | 040/9 6° | 220/8 2° | 230/15 -11° | 220/33 -22° | 220/47 -35° | 230/55 -41° | 230/56 -50° |
| TVC | used from 498 nm out; 153 nm from the line | 210/17 | 290/14 15° | 310/20 9° | 310/18 2° | 310/24 -11° | 320/35 -22° | 320/53 -39° | 310/45 -49° | 290/58 -51° |
| GRB | used from 747 nm out; 143 nm from the line | 240/24 | 260/18 16° | 270/20 11° | 290/14 4° | 280/24 -9° | 300/34 -21° | 310/51 -38° | 310/54 -48° | 300/71 -51° |
| DLH | used from 797 nm out; 125 nm from the line | 240/6 | 230/22 15° | 250/28 11° | 230/22 4° | 270/33 -12° | 280/47 -21° | 280/59 -37° | 290/65 -47° | 290/88 -55° |
| INL | used from 996 nm out; 54 nm from the line | 060/19 | 300/13 11° | 240/19 7° | 230/43 1° | 260/54 -11° | 260/50 -22° | 270/66 -38° | 280/70 -49° | 270/79 -56° |
| GFK | used from 1046 nm out; 81 nm from the line | 050/18 | L/V 10° | 240/20 7° | 240/36 1° | 250/47 -11° | 260/53 -21° | 270/59 -36° | 270/65 -47° | 260/88 -56° |
| MOT | used from 1245 nm out; 47 nm from the line | 070/8 6° | 180/7 2° | 220/18 -1° | 240/37 -11° | 250/55 -20° | 250/64 -36° | 250/70 -46° | 250/80 -54° | |
| GGW | used from 1444 nm out; 63 nm from the line | 090/18 0° | 140/12 -2° | 150/13 -3° | 200/35 -12° | 230/56 -22° | 240/75 -37° | 240/81 -46° | 240/78 -49° | |
| GTF | used from 1644 nm out; 79 nm from the line | 070/21 | 080/18 -6° | 120/5 -5° | 180/30 -14° | 200/53 -24° | 210/80 -38° | 220/83 -44° | 230/68 -46° | |
| GPI | used from 1743 nm out; 67 nm from the line | 060/19 -3° | 110/11 -8° | 130/6 -8° | 200/40 -19° | 190/58 -28° | 200/101 -39° | 220/73 -43° | 230/41 -43° | |
| GEG | used from 1893 nm out; 59 nm from the line | 050/18 -2° | 060/19 -8° | L/V -11° | 160/11 -24° | 190/17 -31° | 200/19 -35° | 220/14 -37° | 250/11 -41° | |
| YKM | used from 2042 nm out; 78 nm from the line | 030/16 | 020/18 0° | 030/30 -8° | 030/23 -13° | 020/40 -23° | 010/73 -29° | 010/54 -36° | 360/29 -37° | 330/16 -40° |
| SEA | used from 2092 nm out; 46 nm from the line | 360/9 | 350/10 1° | 010/10 -5° | 030/20 -11° | 020/60 -17° | 010/86 -26° | 360/90 -40° | 010/68 -42° | 360/31 -43° |
The weather now: both ends and the airports along the way public airports with a weather report within 25 nm of the line, one for each stretch
| Airport | Where | Conditions | Wind | Visibility | Ceiling | Elevation | Reported |
|---|---|---|---|---|---|---|---|
| BOS Boston, MA | departure | no report just now | 19 ft | ||||
| ASH Nashua, NH | 30 nm out, 13 nm north of the line, tower | no report just now | 200 ft | ||||
| ART Watertown, NY | 239 nm out, 3 nm southwest of the line | no report just now | 330 ft | ||||
| DRM Drummond Island, MI | 588 nm out, 3 nm southwest of the line | no report just now | 668 ft | ||||
| SAW Marquette, MI | 737 nm out, 25 nm southwest of the line, tower | no report just now | 1,204 ft | ||||
| FOZ Bigfork, MN | 1006 nm out, 6 nm northwest of the line | no report just now | 1,351 ft | ||||
| GFK Grand Forks, ND | 1155 nm out, 9 nm south of the line, tower | no report just now | 845 ft | ||||
| MOT Minot, ND | 1315 nm out, 7 nm south of the line, tower | no report just now | 1,715 ft | ||||
| LTY Chester, MT | 1703 nm out, 3 nm north of the line | no report just now | 3,184 ft | ||||
| GPI Kalispell, MT | 1833 nm out, 2 nm west of the line, tower | no report just now | 2,976 ft | ||||
| SFF Spokane, WA | 1962 nm out, 24 nm south of the line, tower | no report just now | 1,956 ft | ||||
| BFI Seattle, WA | destination | no report just now | 21 ft |
The highest airport on this list sits at 3,184 ft; the ground between airports is higher still. Check the sectional chart for the terrain and the minimum safe heights along the line.
At BFI when you get there the forecast at the estimated arrival, 11:50 am PDT (18:50 UTC)
BFI has no terminal forecast; use the nearest airport that does.
Temporary flight restrictions on the line or within 25 nm of it
- 6/8802 Foxborough, MA, Saturday, October 17, 2026 through Sunday, October 18, 2026 UTC 19 nm from the route, at the departure end · drones kept away from a public gathering · starts Saturday 17 October · ZBW
- 6/8771 NW NEGAUNEE, MI, Saturday, October 10, 2026 through Thursday, October 15, 2026 UTC 8 nm from the route, 757 nm along the route · a hazard on the ground (fire-fighting, a chemical spill, rescue work) · until 15 October · ZMP
- 6/8665 9NM E HERMAN, MI, Friday, October 9, 2026 through Tuesday, October 13, 2026 UTC 11 nm from the route, 777 nm along the route · a hazard on the ground (fire-fighting, a chemical spill, rescue work) · until 13 October · ZMP
- 6/4348 GRAND FORKS AFB, ND, Sunday, March 8, 2026 through Sunday, November 1, 2026 Local on the route, 1165 nm along the route · security · until 1 November · ZMP
Daylight
Sunset at BOS 6:07 pm EDT (22:07 UTC), at BFI 6:27 pm PDT (01:27 UTC) (civil twilight ends 6:58 pm PDT (01:58 UTC)).
Each restriction opens the FAA's own page with the exact area, heights and times. Ordinary notices to air missions (closed runways, lights out) are not shown: the FAA's notice search is not open to sites like this one at this time.
Radar and forecast charts for the regions crossed government pictures, the latest each time the page loads
Sources: the Aviation Weather Center's data service (SIGMETs, AIRMETs, graphical AIRMETs, pilot reports, winds and temperatures aloft, observations and terminal forecasts), the National Weather Service radar, the Weather Prediction Center's charts, the FAA's temporary flight restriction list and shapes, and the FAA's airport file for the positions, elevations and magnetic variation. Fetched when the page is viewed and kept a few minutes. Each leg is the straight line between its two airports; airways, terrain and airspace are not considered. The airports in detail: General Edward Lawrence Logan International, Boeing Fld/King County International.