Plan a flight · Sun 6:14 pm PDT (01:14 UTC)

Ontario International to Boeing Fld/King County International ONT → BFI

836 nautical miles (962 statute miles) north on a straight line, true course 347°, about 335° magnetic at the departure end (variation 12E). At 120 knots that is 6 h 45 min at the quickest height in today's winds (39,000 ft, a 4-knot tailwind), arriving about 12:59 am PDT (07:59 UTC), after sunset at the destination. Right now ONT is VFR, wind from the west-southwest (240°) at 8 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: 799 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 below 18,000 ft (due to mountain wave) up to 12,000 ft. Over the first 100 nm of the route.
AIRMET SIERRA 6E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the first 40 nm of the route.
AIRMET TANGO 3W: moderate turbulence below 18,000 ft (due to mountain wave) up to 15,000 ft. Over the route from 110 to 309 nm out.
AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the route from 587 to 647 nm out.
AIRMET ZULU 2C: moderate icing up to 14,000 ft. Over the route from 627 to 677 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 ONT.

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

B38M at 14,000 ft, 33 nm east, 5:13 pm PDT (00:13 UTC): moderate turbulence, light rime icing, 8 °C. At the departure end, 33 nm east of the line.
as filed, and in English
```
ONT UA /OV ONT053034/TM 0013/FL140/TP B38M/TA 08/TB MODERATE TURBULENCE/IC LIGHT RIME ICE 190 - 170
```
Report
a routine report filed through ONT
Where
34 nm northeast (053°) of ONT
Time
00:13 UTC
Height
at 14,000 ft
Aircraft
B38M
Temperature
8 °C
Turbulence
moderate turbulence
Icing
light rime ice at 19,000 ft at 17,000 ft
E75L at 18,000 ft, 5 nm northeast, 4:24 pm PDT (23:24 UTC): moderate turbulence from 18,000 ft to 22,000 ft, remarks: mountain wave a 10-knot loss of airspeed entered by zoa fdcs. 209 nm along the route, 5 nm northeast of the line.
as filed, and in English
```
LOL UA /OV BIH300011/TM 2324/FL 180/TP E75L/TB MOD 180-220/RM MTN WAVE /-10 ENTERED BY ZOA FDCS AWC-WEB
```
Report
a routine report filed through LOL
Where
11 nm northwest (300°) of BIH
Time
23:24 UTC
Height
at 18,000 ft
Aircraft
E75L
Turbulence
moderate from 18,000 ft to 22,000 ft
Remarks
mountain wave a 10-knot loss of airspeed entered by zoa fdcs
A21N at 2,000 ft, 12 nm southwest, 6:06 pm PDT (01:06 UTC): remarks: ils 25L haze below the ceiling. At the departure end, 12 nm southwest of the line.
as filed, and in English
```
LAX UA /OV LAX070030/TM 0106/FL020/TP A21N/SK TOPS068 BASES040/RM ILS 25L - HZ BELOW THE CEILING
```
Report
a routine report filed through LAX
Where
30 nm east (070°) of LAX
Time
01:06 UTC
Height
at 2,000 ft
Aircraft
A21N
Sky
TOPS068 BASES040
Remarks
ils 25L haze below the ceiling
A20N at 5,300 ft, 26 nm southwest, 6:00 pm PDT (01:00 UTC): a broken layer from 4,300 ft to 5,300 ft. At the departure end, 26 nm southwest of the line.
as filed, and in English
```
SNA UA /OV SNA/TM 0100/FL053/TP A20N/SK BKN043-TOP053
```
Report
a routine report filed through SNA
Where
over SNA
Time
01:00 UTC
Height
at 5,300 ft
Aircraft
A20N
Sky
a broken layer from 4,300 ft, tops 5,300 ft
A21B at 4,000 ft, 42 nm west, 5:11 pm PDT (00:11 UTC): a broken layer above 4,000 ft, remarks: during the descent RY25L. At the departure end, 42 nm west of the line.
as filed, and in English
```
LAX UA /OV LAX/TM 0011/FL040/TP A21B/SK BKN-BASE040/RM DURD RY25L
```
Report
a routine report filed through LAX
Where
over LAX
Time
00:11 UTC
Height
at 4,000 ft
Aircraft
A21B
Sky
BKN-BASE040
Remarks
during the descent RY25L
E75S at 5,000 ft, 33 nm southwest, 5:00 pm PDT (00:00 UTC): a routine report with nothing remarked on. At the departure end, 33 nm southwest of the line.
as filed, and in English
```
LGB UA /OV LGB180003/TM 0000/FL050/TP E75S/SK OVC43-TOP050
```
Report
a routine report filed through LGB
Where
3 nm south (180°) of LGB
Time
00:00 UTC
Height
at 5,000 ft
Aircraft
E75S
Sky
OVC43-TOP050
B739 at 3,400 ft, 33 nm west, 4:55 pm PDT (23:55 UTC): overcast above 5,400 ft, remarks: bases 3,500 ft. At the departure end, 33 nm west of the line.
as filed, and in English
```
KLAX UA /OV 10 E LAX/TM 2355/FL034/TP B739/SK OVC054/RM BASES 035
```
Report
a routine report filed through KLAX
Where
10 east lax
Time
23:55 UTC
Height
at 3,400 ft
Aircraft
B739
Sky
overcast from 5,400 ft
Remarks
bases 3,500 ft
C172 at 1,400 ft, 37 nm southwest, 3:53 pm PDT (22:53 UTC): remarks: base 3,400 ft. At the departure end, 37 nm southwest of the line.
as filed, and in English
```
TOA UA /OV 4 E KTOA/TM 2253/FL014/TP C172/RM BASE 034
```
Report
a routine report filed through TOA
Where
4 east KTOA
Time
22:53 UTC
Height
at 1,400 ft
Aircraft
C172
Remarks
base 3,400 ft
B757 at 4,000 ft, 32 nm west, 3:38 pm PDT (22:38 UTC): remarks: reduced visibility below the ceiling ILS25L. At the departure end, 32 nm west of the line.
as filed, and in English
```
LAX UA /OV LAX070010/TM 2238/FL040/TP B757/SK TOPS050 BASES040/RM REDUCED VISIBILITY BELOW THE CEILING. ILS25L
```
Report
a routine report filed through LAX
Where
10 nm east (070°) of LAX
Time
22:38 UTC
Height
at 4,000 ft
Aircraft
B757
Sky
TOPS050 BASES040
Remarks
reduced visibility below the ceiling ILS25L
B737 at 4,000 ft, 41 nm west, 3:37 pm PDT (22:37 UTC): a broken layer from 4,000 ft to 5,000 ft. At the departure end, 41 nm west of the line.
as filed, and in English
```
KLAX UA /OV KLAX/TM 2237/FL040/TP B737/SK BKN040-TOP050
```
Report
a routine report filed through KLAX
Where
over KLAX
Time
22:37 UTC
Height
at 4,000 ft
Aircraft
B737
Sky
a broken layer from 4,000 ft, tops 5,000 ft
B737 at 5,000 ft, 34 nm southwest, 3:30 pm PDT (22:30 UTC): a broken layer from 3,300 ft to 5,000 ft. At the departure end, 34 nm southwest of the line.
as filed, and in English
```
LGB UA /OV KLGB180005/TM 2230/FL050/TP B737/SK BKN033-TOPS050
```
Report
a routine report filed through LGB
Where
5 nm south (180°) of KLGB
Time
22:30 UTC
Height
at 5,000 ft
Aircraft
B737
Sky
a broken layer from 3,300 ft, tops 5,000 ft
B739 at 4,000 ft, 35 nm west, 5:32 pm PDT (00:32 UTC): overcast above 4,000 ft. At the departure end, 35 nm west of the line.
as filed, and in English
```
BUR UA /OV BUR/TM 0032/FL040/TP B739/SK OVC040
```
Report
a routine report filed through BUR
Where
over BUR
Time
00:32 UTC
Height
at 4,000 ft
Aircraft
B739
Sky
overcast from 4,000 ft
B739 at 33,000 ft, 3 nm east, 4:02 pm PDT (23:02 UTC): remarks: mountain wave 10 knots zlawc. At the departure end, 3 nm east of the line.
as filed, and in English
```
DRA UA /OV VCV242015/TM 2302/FL330/TP B739/RM MTN WAVE /- 10 KT /ZLAWC AWC-WEB
```
Report
a routine report filed through DRA
Where
15 nm southwest (242°) of VCV
Time
23:02 UTC
Height
at 33,000 ft
Aircraft
B739
Remarks
mountain wave 10 knots zlawc
B739 at 33,000 ft, 14 nm west, 4:01 pm PDT (23:01 UTC): remarks: mountain wave 10 knots zlawc. 40 nm along the route, 14 nm west of the line.
as filed, and in English
```
SDB UA /OV PMD/TM 2301/FL330/TP B739/RM MTN WAVE /- 10 KT /ZLAWC AWC-WEB
```
Report
a routine report filed through SDB
Where
over PMD
Time
23:01 UTC
Height
at 33,000 ft
Aircraft
B739
Remarks
mountain wave 10 knots zlawc

7 more routine reports are on the map.

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 9 forecast points nearest it (ONT, WJF, BIH, RNO, LKV, RDM, PDX, 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	330° at 5 kt	+4 kt	0 °C	116 kt	7 h 12 min	1:26 am PDT (08:26 UTC)
6,500 ft	330° at 4 kt	+4 kt	0 °C	116 kt	7 h 12 min	1:26 am PDT (08:26 UTC)
8,500 ft	340° at 6 kt	+5 kt	-4 °C	115 kt	7 h 16 min	1:30 am PDT (08:30 UTC)
10,500 ft	300° at 4 kt	+3 kt	-5 °C	117 kt	7 h 09 min	1:23 am PDT (08:23 UTC)
12,500 ft	270° at 5 kt	+1 kt	-9 °C	119 kt	7 h 02 min	1:16 am PDT (08:16 UTC)
14,500 ft	290° at 6 kt	+3 kt	-12 °C	117 kt	7 h 09 min	1:23 am PDT (08:23 UTC)
16,500 ft	300° at 6 kt	+4 kt	-16 °C	116 kt	7 h 12 min	1:26 am PDT (08:26 UTC)
18,000 ft FL180	310° at 7 kt	+5 kt	-18 °C	115 kt	7 h 16 min	1:30 am PDT (08:30 UTC)
24,000 ft FL240	320° at 16 kt	+14 kt	-25 °C	106 kt	7 h 53 min	2:07 am PDT (09:07 UTC)
30,000 ft FL300	280° at 20 kt	+8 kt	-31 °C	112 kt	7 h 28 min	1:42 am PDT (08:42 UTC)
34,000 ft FL340	250° at 23 kt	−1 kt	-35 °C	121 kt	6 h 55 min	1:09 am PDT (08:09 UTC)
39,000 ft FL390	250° at 28 kt	−4 kt	-42 °C	124 kt	6 h 45 min	12:59 am PDT (07:59 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
ONT	used from 0 nm out; 25 nm from the line	230/11	200/17 6°	230/27 4°	230/32 -2°	210/39 -12°	220/51 -20°	220/48 -29°	210/51 -34°	210/52 -44°
WJF	used from 50 nm out; 34 nm from the line		220/30 8°	240/28 5°	230/34 -2°	220/34 -13°	220/48 -20°	220/47 -29°	210/48 -34°	220/52 -44°
BIH	used from 100 nm out; 79 nm from the line		L/V	210/14 6°	210/20 -2°	230/26 -14°	220/32 -24°	220/63 -27°	220/56 -35°	230/50 -44°
RNO	used from 249 nm out; 72 nm from the line		320/7	260/13 1°	230/21 -7°	210/38 -17°	220/43 -26°	230/54 -29°	230/59 -32°	230/54 -41°
LKV	used from 398 nm out; 81 nm from the line			010/18 -6°	280/7 -11°	290/9 -22°	280/13 -27°	290/20 -31°	260/19 -34°	260/27 -39°
RDM	used from 548 nm out; 62 nm from the line		010/15 -2°	030/21 -8°	020/26 -12°	020/46 -22°	010/72 -27°	360/47 -34°	340/31 -35°	320/20 -40°
PDX	used from 697 nm out; 45 nm from the line	330/7	360/13 0°	040/22 -6°	030/23 -12°	020/64 -18°	010/93 -25°	010/91 -39°	360/62 -40°	350/41 -43°
YKM	used from 747 nm out; 55 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 796 nm out; 16 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
ONT Ontario, CA	departure	VFR Sky: scattered clouds at 4,900 feet, a broken layer at 12,000 feet	from the west-southwest (240°) at 8 knots	10+ mi	12,000 ft	944 ft	5:53 pm PDT (00:53 UTC)
MHV Mojave, CA	70 nm out, 13 nm southwest of the line, tower	VFR Sky: overcast at 14,000 feet	from the southwest (220°) at 21 knots, gusting to 32	10+ mi	14,000 ft	2,801 ft	22:15 UTC
IYK Inyokern, CA	100 nm out, 12 nm east of the line	no report just now				2,457 ft
MMH Mammoth Lakes, CA	219 nm out, 9 nm west of the line	VFR Sky: scattered clouds at 9,000 feet	from the southeast (140°) at 19 knots, gusting to 30	10+ mi	none	7,134 ft	23:35 UTC
SPZ Silver Springs, NV	329 nm out, 2 nm northwest of the line	no report just now				4,265 ft
RNO Reno, NV	339 nm out, 23 nm west of the line, tower	VFR Sky: scattered clouds at 9,000 feet	from the north (360°) at 14 knots, gusting to 22	10+ mi	none	4,414 ft	00:55 UTC
LKV Lakeview, OR	508 nm out, 10 nm southwest of the line	VFR	from the north-northeast (020°) at 14 knots	10+ mi	none	4,734 ft	00:53 UTC
RDM Redmond, OR	637 nm out, 8 nm southwest of the line, tower	VFR Sky: overcast at 6,500 feet	from the north (350°) at 8 knots	10+ mi	6,500 ft	3,081 ft	00:56 UTC
DLS The Dalles, OR	717 nm out, 14 nm east of the line	VFR Sky: overcast at 9,000 feet	from the west-southwest (240°) at 4 knots	10+ mi	9,000 ft	246 ft	00:53 UTC
PLU Puyallup, WA	816 nm out, 8 nm southwest of the line	VFR Weather: light drizzle	calm	10+ mi	none	537 ft	23:35 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 7,134 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, 12:59 am PDT (07:59 UTC)

Wind light and variable, visibility more than 6 miles, 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 ONT, the departure

From Sun 5:00 pm PDT (00:00 UTC): wind from the southwest at 11 knots, gusting to 18, visibility more than 6 miles, a few clouds at 3,000 feet, a broken layer at 5,000 feet
From Sun 11:00 pm PDT (06:00 UTC): wind from the west-southwest at 8 knots, visibility more than 6 miles, showers nearby, overcast at 2,500 feet
From Mon 3:00 am PDT (10:00 UTC): wind from the west-southwest at 4 knots, visibility more than 6 miles, showers nearby, a few clouds at 2,500 feet, a broken layer at 5,000 feet
From Mon 11:00 am PDT (18:00 UTC): wind from the west-southwest at 5 knots, visibility more than 6 miles, a broken layer at 5,000 feet
From Mon 2:00 pm PDT (21:00 UTC): wind from the west-southwest at 11 knots, gusting to 18, visibility more than 6 miles, a broken layer at 5,000 feet
From Mon 8:00 pm PDT (03:00 UTC): wind from the west-southwest at 9 knots, visibility more than 6 miles, a broken layer at 6,000 feet

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

4/3635 DISNEYLAND THEME PARK, ANAHEIM,, CA 19 nm from the route, at the departure end · security · ZLA
6/8783 38NM NE BAKERSFIELD, CA, Saturday, October 10, 2026 through Friday, October 23, 2026 UTC 10 nm from the route, 110 nm along the route · a hazard on the ground (fire-fighting, a chemical spill, rescue work) · until 23 October · ZLA

Daylight

Sunset at ONT 6:20 pm PDT (01:20 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 Pacific Southwest · 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: Ontario International, Boeing Fld/King County International.