Plan a flight · Sun 8:13 pm CDT (01:13 UTC)

University Of Illinois/Willard Airport to Boeing Fld/King County International CMI → BFI

1,528 nautical miles (1,758 statute miles) northwest on a straight line, true course 298°, about 301° magnetic at the departure end (variation 3W). At 120 knots that is 12 h 02 min at the quickest height in today's winds (4,500 ft, a 7-knot tailwind), arriving about 6:15 am PDT (13:15 UTC), after sunset at the destination. Right now CMI is VFR, wind from the south-southwest (210°) at 3 knots; BFI is VFR, wind from the northwest (310°) at 6 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: 6 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 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 589 to 1258 nm out.
AIRMET TANGO 4W: moderate turbulence above 18,000 ft from 18,000 ft to 36,000 ft. Over the route from 719 to 1268 nm out.
AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the route from 929 to 1328 nm out.
AIRMET TANGO 4W: moderate turbulence below 18,000 ft up to 18,000 ft. Near the route, 969 nm along the route.
AIRMET ZULU 2C: moderate icing up to 14,000 ft. Over the route from 1188 to 1408 nm out.
AIRMET TANGO 1W: moderate turbulence above 18,000 ft from 25,000 ft to 39,000 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 CMI.

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

E75L at 14,000 ft, 16 nm south, 6:22 pm CDT (23:22 UTC): moderate turbulence from 14,000 ft to 21,000 ft, remarks: during the climb zlc. 1188 nm along the route, 16 nm south of the line.
as filed, and in English
```
MSO UA /OV 32S/TM 2322/FL140/TP E75L/TB MOD 140-210/RM DURC /ZLC
```
Report
a routine report filed through MSO
Where
over 32S
Time
23:22 UTC
Height
at 14,000 ft
Aircraft
E75L
Turbulence
moderate from 14,000 ft to 21,000 ft
Remarks
during the climb zlc
PC12 at 100 ft, 18 nm north, 5:34 pm CDT (22:34 UTC): no icing. 589 nm along the route, 18 nm north of the line.
as filed, and in English
```
PIR UA /OV PIR/TM 2234/FL001/TP PC12/SK BASE030-TOP045/IC NEG
```
Report
a routine report filed through PIR
Where
over PIR
Time
22:34 UTC
Height
at 100 ft
Aircraft
PC12
Sky
BASE030-TOP045
Icing
none
A306 at 4,700 ft, 9 nm south, 7:51 pm CDT (00:51 UTC): a routine report with nothing remarked on. 959 nm along the route, 9 nm south of the line.
as filed, and in English
```
BIL UA /OV BIL280001/TM 0051/FL047/TP A306/SK BASE 047
```
Report
a routine report filed through BIL
Where
1 nm west (280°) of BIL
Time
00:51 UTC
Height
at 4,700 ft
Aircraft
A306
Sky
base 4,700 ft
E75L descending, 35 nm south, 8:04 pm CDT (01:04 UTC): remarks: had the airport in sight at 400-500FT above ground. 1059 nm along the route, 35 nm south of the line.
as filed, and in English
```
BZN UA /OV BZN/TM 0104/FLDURD/TP E75L/RM HAD THE AIRPORT IN SIGHT AT 400-500FT AGL
```
Report
a routine report filed through BZN
Where
over BZN
Time
01:04 UTC
Height
during the descent
Aircraft
E75L
Remarks
had the airport in sight at 400-500FT above ground
B737 descending, 35 nm south, 7:28 pm CDT (00:28 UTC): scattered clouds above 8,000 ft, fog, snow, remarks: broke out about 100FT above mins. 1059 nm along the route, 35 nm south of the line.
as filed, and in English
```
BZN UA /OV BZN/TM 0028/FLDURD/TP B737/SK SCT080/WX 1/2SM SN FG/RM BROKE OUT ABOUT 100FT ABOVE MINS
```
Report
a routine report filed through BZN
Where
over BZN
Time
00:28 UTC
Height
during the descent
Aircraft
B737
Sky
scattered clouds from 8,000 ft
Weather
1/2SM, snow, fog
Remarks
broke out about 100FT above mins
B738 at 24,000 ft, 32 nm south, 6:13 pm CDT (23:13 UTC): remarks: snow top flight level at 24,000 ft zlc. 1089 nm along the route, 32 nm south of the line.
as filed, and in English
```
BZN UA /OV BZN270030/TM 2313/FL240/TP B738/RM SN TOP FL 240 /ZLC
```
Report
a routine report filed through BZN
Where
30 nm west (270°) of BZN
Time
23:13 UTC
Height
at 24,000 ft
Aircraft
B738
Remarks
snow top flight level at 24,000 ft zlc
C25B at 4,100 ft, 7 nm north, 7:36 pm CDT (00:36 UTC): no icing, overcast above 4,100 ft, remarks: during the descent ils runway 12. 1188 nm along the route, 7 nm north of the line.
as filed, and in English
```
MSO UA /OV MSO/TM 0036/FL041/TP C25B/SK OVC041/IC NEG/RM DURD ILS RY 12
```
Report
a routine report filed through MSO
Where
over MSO
Time
00:36 UTC
Height
at 4,100 ft
Aircraft
C25B
Sky
overcast from 4,100 ft
Icing
none
Remarks
during the descent ils runway 12
C172 at 5,500 ft, 32 nm south, 5:17 pm CDT (22:17 UTC): a trace of rime icing, 0 °C, remarks: zse. 1348 nm along the route, 32 nm south of the line.
as filed, and in English
```
PUW UA /OV PUW250030/TM 2217/FL055/TP C172/TA 00/IC TRACE RIME/RM -ZSE
```
Report
a routine report filed through PUW
Where
30 nm west (250°) of PUW
Time
22:17 UTC
Height
at 5,500 ft
Aircraft
C172
Temperature
0 °C
Icing
trace rime
Remarks
zse
PC12 at 13,000 ft, 38 nm south, 7:42 pm CDT (00:42 UTC): remarks: zse. At the destination end, 38 nm south of the line.
as filed, and in English
```
YKM UA /OV YKM270050/TM 0042/FL130/TP PC12/SK TOP130/RM -ZSE
```
Report
a routine report filed through YKM
Where
50 nm west (270°) of YKM
Time
00:42 UTC
Height
at 13,000 ft
Aircraft
PC12
Sky
TOP130
Remarks
zse
PC12 at 15,000 ft, 38 nm south, 7:42 pm CDT (00:42 UTC): remarks: zse. At the destination end, 38 nm south of the line.
as filed, and in English
```
YKM UA /OV YKM270050/TM 0042/FL150/TP PC12/SK TOP130/RM -ZSE
```
Report
a routine report filed through YKM
Where
50 nm west (270°) of YKM
Time
00:42 UTC
Height
at 15,000 ft
Aircraft
PC12
Sky
TOP130
Remarks
zse

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 14 forecast points nearest it (SPI, BRL, DSM, FSD, PIR, RAP, MLS, BIL, GTF, GPI, LWS, 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	120° at 5 kt	−7 kt	7 °C	127 kt	12 h 02 min	6:15 am PDT (13:15 UTC)
6,500 ft	130° at 3 kt	−4 kt	9 °C	124 kt	12 h 19 min	6:32 am PDT (13:32 UTC)
8,500 ft	200° at 5 kt	−1 kt	6 °C	121 kt	12 h 38 min	6:51 am PDT (13:51 UTC)
10,500 ft	220° at 9 kt	+2 kt	2 °C	118 kt	12 h 57 min	7:10 am PDT (14:10 UTC)
12,500 ft	220° at 13 kt	+5 kt	-1 °C	115 kt	13 h 17 min	7:30 am PDT (14:30 UTC)
14,500 ft	230° at 15 kt	+7 kt	-5 °C	113 kt	13 h 31 min	7:44 am PDT (14:44 UTC)
16,500 ft	230° at 17 kt	+9 kt	-9 °C	111 kt	13 h 46 min	7:59 am PDT (14:59 UTC)
18,000 ft FL180	230° at 19 kt	+11 kt	-12 °C	109 kt	14 h 01 min	8:14 am PDT (15:14 UTC)
24,000 ft FL240	240° at 25 kt	+16 kt	-23 °C	104 kt	14 h 42 min	8:55 am PDT (15:55 UTC)
30,000 ft FL300	240° at 32 kt	+22 kt	-36 °C	98 kt	15 h 36 min	9:49 am PDT (16:49 UTC)
34,000 ft FL340	250° at 40 kt	+31 kt	-42 °C	89 kt	17 h 10 min	11:23 am PDT (18:23 UTC)
39,000 ft FL390	260° at 46 kt	+41 kt	-48 °C	79 kt	19 h 21 min	1:34 pm PDT (20:34 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
SPI	used from 0 nm out; 48 nm from the line	210/13	260/11 17°	270/18 10°	290/21 4°	310/20 -8°	330/25 -19°	320/49 -34°	320/60 -44°	320/59 -50°
BRL	used from 100 nm out; 23 nm from the line	200/20	250/21 16°	240/22 10°	260/20 5°	270/16 -7°	290/22 -18°	320/41 -34°	320/56 -43°	310/68 -53°
DSM	used from 200 nm out; 45 nm from the line	200/32	240/27 17°	260/19 10°	260/16 5°	260/19 -7°	240/22 -19°	270/20 -32°	270/38 -42°	290/58 -53°
FSD	used from 350 nm out; 65 nm from the line	200/16	220/20 17°	240/26 13°	230/19 6°	240/25 -9°	240/28 -20°	250/39 -33°	250/44 -43°	260/63 -52°
PIR	used from 499 nm out; 71 nm from the line		L/V 17°	230/13 12°	220/22 6°	250/31 -9°	250/34 -21°	240/50 -35°	230/61 -43°	240/62 -51°
RAP	used from 649 nm out; 50 nm from the line		120/15 12°	180/22 11°	220/26 5°	230/35 -9°	240/40 -22°	240/50 -37°	240/51 -41°	240/47 -47°
MLS	used from 799 nm out; 66 nm from the line		120/22 5°	170/18 4°	200/33 1°	230/49 -10°	230/58 -21°	220/54 -37°	230/64 -44°	250/74 -49°
BIL	used from 899 nm out; 30 nm from the line		080/24	130/14 -1°	180/33 0°	210/43 -10°	220/58 -21°	200/55 -36°	220/75 -44°	240/83 -48°
GTF	used from 1049 nm out; 65 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 1149 nm out; 97 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°
LWS	used from 1248 nm out; 55 nm from the line	010/5	050/14 -2°	040/12 -6°	160/7 -10°	190/30 -22°	200/54 -27°	200/48 -35°	210/40 -37°	230/32 -41°
GEG	used from 1298 nm out; 30 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 1398 nm out; 58 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 1448 nm out; 55 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
CMI Champaign/Urbana, IL	departure	VFR	from the south-southwest (210°) at 3 knots	10+ mi	none	754 ft	7:53 pm CDT (00:53 UTC)
PIA Peoria, IL	70 nm out, 6 nm northwest of the line, tower	VFR	calm	10+ mi	none	660 ft	00:54 UTC
AMW Ames, IA	270 nm out, 4 nm south of the line	VFR	from the south-southeast (150°) at 7 knots	10+ mi	none	955 ft	00:53 UTC
SLB Storm Lake, IA	350 nm out, 1 nm south of the line	VFR	from the south (170°) at 7 knots	10+ mi	none	1,487 ft	00:55 UTC
PIR Pierre, SD	589 nm out, 16 nm north of the line	marginal VFR Sky: a few clouds at 500 feet, overcast at 1,100 feet	from the east-northeast (070°) at 5 knots	10+ mi	1,100 ft	1,744 ft	00:53 UTC
EFC Belle Fourche, SD	749 nm out, 15 nm south of the line	no report just now				3,190 ft
BIL Billings, MT	949 nm out, 9 nm southwest of the line, tower	IFR Sky: a broken layer at 800 feet, overcast at 1,200 feet Weather: light rain	from the north (010°) at 15 knots	10+ mi	800 ft	3,662 ft	00:53 UTC
HLN Helena, MT	1099 nm out, 7 nm northwest of the line, tower	IFR Sky: scattered clouds at 600 feet, overcast at 1,200 feet Weather: light snow, mist	from the west-northwest (290°) at 8 knots	1 mi	1,200 ft	3,877 ft	01:01 UTC
PUW Pullman/Moscow, WA	1308 nm out, 24 nm south of the line	VFR Sky: overcast at 5,500 feet	from the north (010°) at 8 knots	10+ mi	5,500 ft	2,566 ft	00:53 UTC
MWH Moses Lake, WA	1408 nm out, 8 nm south of the line, tower	VFR Sky: overcast at 10,000 feet	from the northeast (050°) at 13 knots, gusting to 18	10+ mi	10,000 ft	1,188 ft	00:52 UTC
BFI Seattle, WA	destination	VFR	from the northwest (310°) at 6 knots	10+ mi	none	21 ft	5:53 pm PDT (00:53 UTC)

The highest airport on this list sits at 3,877 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, 6:15 am PDT (13:15 UTC)

Wind light and variable, visibility more than 6 miles, patches of fog, clear skies VFR

The whole forecast for BFI

From Sun 5:00 pm PDT (00:00 UTC): wind from the north-northwest at 8 knots, gusting to 18, visibility more than 6 miles, a few clouds at 5,000 feet
From Sun 7:00 pm PDT (02:00 UTC): wind light and variable, visibility more than 6 miles, clear skies
From Mon 3:00 am PDT (10:00 UTC): wind light and variable, visibility more than 6 miles, patches of fog, clear skies
From Mon 9:00 am PDT (16:00 UTC): wind from the south-southeast at 3 knots, visibility more than 6 miles, clear skies
From Mon 12:00 pm PDT (19:00 UTC): wind from the west-southwest at 3 knots, visibility more than 6 miles, clear skies
From Mon 2:00 pm PDT (21:00 UTC): wind from the west at 5 knots, visibility more than 6 miles, clear skies

The forecast for CMI, the departure

From Sun 7:00 pm CDT (00:00 UTC): wind from the south at 6 knots, visibility more than 6 miles, a few clouds at 25,000 feet
From Mon 4:00 am CDT (09:00 UTC): wind from the south-southwest at 8 knots, visibility more than 6 miles, scattered clouds at 18,000 feet, a broken layer at 25,000 feet
From Mon 12:00 pm CDT (17:00 UTC): wind from the southwest at 12 knots, gusting to 19, visibility more than 6 miles, scattered clouds at 10,000 feet, a broken layer at 18,000 feet

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

No temporary flight restriction on or near this route right now.

Daylight

Sunset at CMI 6:18 pm CDT (23:18 UTC), at BFI 6:27 pm PDT (01:27 UTC) (civil twilight ends 6:58 pm PDT (01:58 UTC)). At 120 knots the arrival at BFI is before sunrise there (7:23 am PDT (14:23 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 upper Mississippi valley · loop National Weather Service

Radar now, the northern Rockies · loop National Weather Service

Radar now, the Pacific Northwest · 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: University Of Illinois/Willard Airport, Boeing Fld/King County International.