Plan a flight · Mon 8:06 am PDT (15:06 UTC)

Boeing Fld/King County International to Billings Logan International BFI → BIL

575 nautical miles (662 statute miles) east on a straight line, true course 095°, about 080° magnetic at the departure end (variation 15E). At 120 knots that is 4 h 16 min at the quickest height in today's winds (39,000 ft, a 15-knot tailwind), arriving about 1:22 pm MDT (19:22 UTC). Right now BFI is VFR, wind from the south-southeast (160°) at 3 knots; BIL is VFR, wind from the southwest (230°) at 3 knots. 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: 3 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 TANGO 1W: moderate turbulence above 18,000 ft from 18,000 ft to 39,000 ft. Over the route from 50 to 337 nm out.
AIRMET ZULU 2C: moderate icing up to 18,000 ft. Over the route from 179 to 565 nm out.
AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the last 347 nm of the route.
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 last 198 nm of the route.
AIRMET ZULU 2C: moderate icing up to 23,000 ft. Over the last 0 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 BFI.

Pilot reports along the route within 50 nm of the line, last three hours, the serious ones first

SR22 at 6,000 ft, 18 nm northeast, 7:12 am PDT (14:12 UTC): a trace of rime icing. 188 nm along the route, 18 nm northeast of the line.
as filed, and in English
```
GEG UA /OV GEG140009/TM 1412/FL060/TP SR22/IC TRACE RIME OAT M4
```
Report
a routine report filed through GEG
Where
9 nm southeast (140°) of GEG
Time
14:12 UTC
Height
at 6,000 ft
Aircraft
SR22
Icing
trace rime oat −4 °C
A320 at 25,000 ft, 32 nm north, 6:25 am PDT (13:25 UTC): light to moderate chop turbulence above 25,000 ft, remarks: zse. 268 nm along the route, 32 nm north of the line.
as filed, and in English
```
MLP UA /OV MLP/TM 1325/FL250/TP A320/TB CONS LGT OCNL MOD CHOP 250 /RM ZSE
```
Report
a routine report filed through MLP
Where
over MLP
Time
13:25 UTC
Height
at 25,000 ft
Aircraft
A320
Turbulence
continuous light occasional moderate chop at 25,000 ft
Remarks
zse
C25B at 11,000 ft, 11 nm north, 7:13 am PDT (14:13 UTC): a routine report with nothing remarked on. 337 nm along the route, 11 nm north of the line.
as filed, and in English
```
MSO UA /OV MSO/TM 1413/FL110/TP C25B/SK TOP 110
```
Report
a routine report filed through MSO
Where
over MSO
Time
14:13 UTC
Height
at 11,000 ft
Aircraft
C25B
Sky
top 11,000 ft
B752 at 41,000 ft, 22 nm north, 5:31 am PDT (12:31 UTC): light to moderate turbulence above 41,000 ft. 427 nm along the route, 22 nm north of the line.
as filed, and in English
```
HLN UA /OV HLN009010/TM 1231/FL410/TP B752/TB CONS LGT OCNL MOD 410/ZLC
```
Report
a routine report filed through HLN
Where
10 nm north (009°) of HLN
Time
12:31 UTC
Height
at 41,000 ft
Aircraft
B752
Turbulence
continuous light occasional moderate 410/ZLC
BE9L at 7,500 ft, 7 nm north, 5:45 am PDT (12:45 UTC): no turbulence, light rime icing, overcast from 7,500 ft to 9,000 ft, -6 °C, remarks: during the climb. 437 nm along the route, 7 nm north of the line.
as filed, and in English
```
HLN UA /OV HLN120010/TM 1245/FL075/TP BE9L/SK OVC075-TOPS090/TA M06/TB NEG/IC LGT RIME/RM DURC
```
Report
a routine report filed through HLN
Where
10 nm southeast (120°) of HLN
Time
12:45 UTC
Height
at 7,500 ft
Aircraft
BE9L
Sky
overcast from 7,500 ft, tops 9,000 ft
Temperature
−6 °C
Turbulence
none
Icing
light rime
Remarks
during the climb
GLF4 descending, 29 nm south, 6:48 am PDT (13:48 UTC): a routine report with nothing remarked on. 466 nm along the route, 29 nm south of the line.
as filed, and in English
```
BZN UA /OV BZN/TM 1348/FLDURD/TP GLF4/SK 047
```
Report
a routine report filed through BZN
Where
over BZN
Time
13:48 UTC
Height
during the descent
Aircraft
GLF4
Sky
at 4,700 ft
C340 descending, 29 nm south, 5:47 am PDT (12:47 UTC): light icing, remarks: smooth. 466 nm along the route, 29 nm south of the line.
as filed, and in English
```
BZN UA /OV BZN/TM 1247/FLDURD/TP C340/SK 055/IC LGT RM/RM SMOOTH
```
Report
a routine report filed through BZN
Where
over BZN
Time
12:47 UTC
Height
during the descent
Aircraft
C340
Sky
at 5,500 ft
Icing
light remarks
Remarks
smooth
C25A at 5,000 ft, 3 nm west, 6:00 am PDT (13:00 UTC): light rime icing, 4 °C, remarks: lt rime in the descent. At the destination end, 3 nm west of the line.
as filed, and in English
```
BIL UA /OV 100006/TM 1300/FL050/TP C25A/TA 4/IC LT RIME/RM LT RIME IN THE DESCENT
```
Report
a routine report filed through BIL
Where
wind from 100° at 6 knots
Time
13:00 UTC
Height
at 5,000 ft
Aircraft
C25A
Temperature
4 °C
Icing
lt rime
Remarks
lt rime in the descent

Winds aloft along the route, and the time en route the forecast for use 14:00–21:00 UTC · at 120 knots true airspeed

The eastbound cruising heights for this course (VFR: odd thousands plus 500 ft; above 18,000 ft the forecast levels), with the wind averaged along the line from the 8 forecast points nearest it (SEA, YKM, GEG, LWS, GPI, DLN, GTF, BIL). A plus sign is a headwind, a minus sign a tailwind.

Height	Average wind	Head- or tailwind	Temperature	Ground speed	Time en route	Arrival
5,500 ft	020° at 2 kt	0	-2 °C	120 kt	4 h 48 min	1:54 pm MDT (19:54 UTC)
7,500 ft	020° at 4 kt	+1 kt	-3 °C	119 kt	4 h 50 min	1:56 pm MDT (19:56 UTC)
9,500 ft	030° at 5 kt	+2 kt	-4 °C	118 kt	4 h 52 min	1:58 pm MDT (19:58 UTC)
11,500 ft	020° at 4 kt	+1 kt	-6 °C	119 kt	4 h 50 min	1:56 pm MDT (19:56 UTC)
13,500 ft	030° at 3 kt	+2 kt	-9 °C	118 kt	4 h 52 min	1:58 pm MDT (19:58 UTC)
15,500 ft	030° at 4 kt	+3 kt	-13 °C	117 kt	4 h 55 min	2:01 pm MDT (20:01 UTC)
17,500 ft	040° at 4 kt	+3 kt	-17 °C	117 kt	4 h 55 min	2:01 pm MDT (20:01 UTC)
18,000 ft FL180	040° at 4 kt	+4 kt	-18 °C	116 kt	4 h 57 min	2:03 pm MDT (20:03 UTC)
24,000 ft FL240	010° at 5 kt	+1 kt	-29 °C	119 kt	4 h 50 min	1:56 pm MDT (19:56 UTC)
30,000 ft FL300	260° at 6 kt	−3 kt	-38 °C	123 kt	4 h 40 min	1:46 pm MDT (19:46 UTC)
34,000 ft FL340	230° at 13 kt	−7 kt	-40 °C	127 kt	4 h 32 min	1:38 pm MDT (19:38 UTC)
39,000 ft FL390	230° at 28 kt	−15 kt	-43 °C	135 kt	4 h 16 min	1:22 pm MDT (19:22 UTC)

Based on data from the 12th at 12:00 UTC; valid on the 12th at 18:00 UTC for use 14:00 to 21:00 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
SEA	used from 0 nm out; 25 nm from the line	L/V	L/V 1°	020/13 -2°	020/27 -4°	010/43 -14°	360/54 -26°	360/63 -40°	010/60 -48°	350/39 -50°
YKM	used from 50 nm out; 50 nm from the line	L/V	350/9 0°	040/20 -5°	030/23 -8°	020/41 -18°	010/74 -27°	010/73 -40°	020/54 -44°	350/9 -43°
GEG	used from 149 nm out; 34 nm from the line		060/10 -2°	050/11 -3°	050/9 -8°	050/27 -19°	040/26 -31°	030/32 -39°	020/19 -41°	L/V -42°
LWS	used from 198 nm out; 41 nm from the line	L/V	L/V -2°	030/6 -5°	050/10 -10°	110/19 -21°	150/22 -31°	130/11 -36°	200/6 -37°	220/21 -40°
GPI	used from 298 nm out; 93 nm from the line		L/V -3°	L/V -4°	L/V -6°	210/19 -17°	220/26 -32°	190/23 -40°	220/25 -39°	220/34 -42°
DLN	used from 347 nm out; 87 nm from the line			L/V -3°	170/16 -6°	180/21 -18°	190/27 -30°	210/63 -33°	210/62 -36°	210/51 -42°
GTF	used from 397 nm out; 71 nm from the line		L/V	L/V -4°	230/12 -3°	210/12 -17°	190/23 -29°	200/48 -39°	210/69 -39°	220/66 -42°
BIL	used from 496 nm out; 55 nm from the line		L/V	250/11 -1°	240/20 -2°	230/28 -15°	220/28 -28°	220/53 -34°	220/55 -39°	220/63 -44°

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
BFI Seattle, WA	departure	VFR	from the south-southeast (160°) at 3 knots	10+ mi	none	21 ft	7:53 am PDT (14:53 UTC)
ESW Easton, WA	50 nm out, 12 nm south of the line	no report just now				2,226 ft
EAT Wenatchee, WA	89 nm out, 4 nm northwest of the line	reported, no category	from the north-northwest (340°) at 5 knots		none	1,248 ft	14:55 UTC
MWH Moses Lake, WA	119 nm out, 7 nm southeast of the line, tower	VFR	from the north (010°) at 5 knots	10+ mi	none	1,188 ft	14:52 UTC
PUW Pullman/Moscow, WA	218 nm out, 21 nm south of the line	VFR Sky: overcast at 3,400 feet	from the northeast (040°) at 3 knots	10+ mi	3,400 ft	2,566 ft	14:53 UTC
MSO Missoula, MT	337 nm out, 12 nm north of the line, tower	VFR Sky: overcast at 6,500 feet	calm	10+ mi	6,500 ft	3,205 ft	14:53 UTC
HLN Helena, MT	427 nm out, 12 nm north of the line, tower	marginal VFR Sky: overcast at 1,800 feet	from the west (280°) at 6 knots	10+ mi	1,800 ft	3,877 ft	14:53 UTC
HWQ Harlowton, MT	516 nm out, 23 nm north of the line	no report just now				4,311 ft
BIL Billings, MT	destination	VFR Sky: a few clouds at 500 feet, a few clouds at 2,100 feet, scattered clouds at 3,700 feet	from the southwest (230°) at 3 knots	10+ mi	none	3,662 ft	8:53 am MDT (14:53 UTC)

The highest airport on this list sits at 4,311 ft; the ground between airports is higher still. Check the sectional chart for the terrain and the minimum safe heights along the line.

At BIL when you get there the forecast at the estimated arrival, 1:22 pm MDT (19:22 UTC)

Wind light and variable, visibility more than 6 miles, scattered clouds at 1,500 feet, overcast at 2,500 feet marginal VFR

The whole forecast for BIL

From Mon 6:00 am MDT (12:00 UTC): wind from the north-northwest at 8 knots, visibility more than 6 miles, light rain snow, a broken layer at 1,200 feet, overcast at 2,200 feet
From Mon 1:00 pm MDT (19:00 UTC): wind light and variable, visibility more than 6 miles, scattered clouds at 1,500 feet, overcast at 2,500 feet
From Mon 6:00 pm MDT (00:00 UTC): wind from the east at 9 knots, visibility 6 miles, light drizzle, mist, a few clouds at 300 feet, overcast at 1,800 feet
From Mon 10:00 pm MDT (04:00 UTC): wind from the east at 9 knots, visibility 4 miles, light drizzle, mist, scattered clouds at 300 feet, overcast at 1,200 feet
From Tue 3:00 am MDT (09:00 UTC): wind light and variable, visibility 3 miles, light rain, mist, scattered clouds at 300 feet, a broken layer at 1,200 feet and more above

The forecast for BFI, the departure

From Mon 5:00 am PDT (12:00 UTC): wind light and variable, visibility more than 6 miles, clear skies
From Mon 12:00 pm PDT (19:00 UTC): wind from the west-southwest at 4 knots, visibility more than 6 miles, clear skies
From Mon 2:00 pm PDT (21:00 UTC): wind from the west-northwest at 5 knots, visibility more than 6 miles, clear skies
From Mon 8:00 pm PDT (03:00 UTC): wind calm, visibility more than 6 miles, scattered clouds at 25,000 feet
From Tue 4:00 am PDT (11:00 UTC): wind from the south-southeast at 4 knots, visibility more than 6 miles, overcast at 10,000 feet

Temporary flight restrictions on the line or within 25 nm of it

6/8927 Kalispell, MT, Wednesday, October 14, 2026 through Wednesday, October 14, 2026 Local on the route, 317 nm along the route · a VIP movement · starts Wednesday 14 October · ZSE
6/8923 Kalispell, MT, Wednesday, October 14, 2026 through Wednesday, October 14, 2026 Local on the route, 317 nm along the route · a VIP movement · starts Wednesday 14 October · ZLC

Daylight

Sunset at BFI 6:25 pm PDT (01:25 UTC), at BIL 6:32 pm MDT (00:32 UTC) (civil twilight ends 7:02 pm MDT (01:02 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

Radar now, the Pacific Northwest · loop National Weather Service

Radar now, the northern Rockies · loop National Weather Service

Radar, the whole country · loop National Weather Service

Surface analysis now Weather Prediction Center

Forecast chart, 12 hours ahead Weather Prediction Center

Forecast chart, 24 hours ahead Weather Prediction Center

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: Boeing Fld/King County International, Billings Logan International.