Great Falls International to San Francisco International GTF → SFO
765 nautical miles (880 statute miles) southwest on a straight line, true course 223°, about 210° magnetic at the departure end (variation 13E). At 120 knots that is 6 h 10 min at the quickest height in today's winds (4,500 ft, a 4-knot tailwind), arriving about 5:57 am PDT (12:57 UTC), after sunset at the destination. 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: 2 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 first 258 nm of the route.
- AIRMET ZULU 2C: moderate icing up to 23,000 ft. Over the first 169 nm of the route.
- AIRMET TANGO 1W: moderate turbulence above 18,000 ft from 18,000 ft to 36,000 ft. Over the first 378 nm of the route.
- AIRMET SIERRA 1E: mountains obscured by cloud (due to mountains obscured by clouds, precipitation, mist). Over the first 288 nm of the route.
- AIRMET ZULU 2C: moderate icing up to 23,000 ft. Over the route from 179 to 278 nm out.
- AIRMET TANGO 1W: moderate turbulence above 18,000 ft from 18,000 ft to 39,000 ft. Over the last 258 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 GTF.
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 02:00–09:00 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 8 forecast points nearest it (GTF, DLN, BOI, BAM, LKV, RNO, SAC, SFO). 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 | 010° at 4 kt | −4 kt | 2 °C | 124 kt | 6 h 10 min | 5:57 am PDT (12:57 UTC) |
| 6,500 ft | 010° at 4 kt | −4 kt | 2 °C | 124 kt | 6 h 10 min | 5:57 am PDT (12:57 UTC) |
| 8,500 ft | 010° at 4 kt | −4 kt | -3 °C | 124 kt | 6 h 10 min | 5:57 am PDT (12:57 UTC) |
| 10,500 ft | 250° at 3 kt | +3 kt | -6 °C | 117 kt | 6 h 32 min | 6:19 am PDT (13:19 UTC) |
| 12,500 ft | 220° at 11 kt | +11 kt | -9 °C | 109 kt | 7 h 01 min | 6:48 am PDT (13:48 UTC) |
| 14,500 ft | 220° at 17 kt | +17 kt | -12 °C | 103 kt | 7 h 26 min | 7:13 am PDT (14:13 UTC) |
| 16,500 ft | 220° at 24 kt | +23 kt | -15 °C | 97 kt | 7 h 53 min | 7:40 am PDT (14:40 UTC) |
| 18,000 ft FL180 | 210° at 28 kt | +28 kt | -18 °C | 92 kt | 8 h 19 min | 8:06 am PDT (15:06 UTC) |
| 24,000 ft FL240 | 220° at 32 kt | +32 kt | -26 °C | 88 kt | 8 h 42 min | 8:29 am PDT (15:29 UTC) |
| 30,000 ft FL300 | 220° at 38 kt | +38 kt | -32 °C | 82 kt | 9 h 20 min | 9:07 am PDT (16:07 UTC) |
| 34,000 ft FL340 | 220° at 50 kt | +49 kt | -35 °C | 71 kt | 10 h 46 min | 10:33 am PDT (17:33 UTC) |
| 39,000 ft FL390 | 220° at 49 kt | +49 kt | -41 °C | 71 kt | 10 h 46 min | 10:33 am PDT (17:33 UTC) |
Based on data from the 12th at 00:00 UTC; valid on the 12th at 06:00 UTC for use 02:00 to 09:00 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 |
|---|---|---|---|---|---|---|---|---|---|---|
| GTF | used from 0 nm out; 25 nm from the line | 070/11 | 080/15 -7° | 110/19 -9° | 190/25 -14° | 200/34 -23° | 200/54 -39° | 220/66 -40° | 220/77 -44° | |
| DLN | used from 99 nm out; 55 nm from the line | 090/6 -6° | 240/22 -4° | 210/34 -16° | 210/62 -25° | 210/66 -34° | 210/82 -36° | 220/77 -42° | ||
| BOI | used from 199 nm out; 88 nm from the line | 300/7 2° | 280/5 -4° | 210/16 -9° | 210/60 -20° | 210/75 -29° | 210/63 -32° | 220/64 -32° | 220/54 -39° | |
| BAM | used from 397 nm out; 104 nm from the line | 310/7 0° | 270/19 -7° | 200/38 -17° | 190/49 -28° | 220/69 -29° | 220/63 -33° | 230/48 -41° | ||
| LKV | used from 447 nm out; 91 nm from the line | 010/8 -8° | 350/13 -11° | 340/21 -21° | 360/60 -26° | 350/37 -32° | 310/26 -35° | 260/25 -39° | ||
| RNO | used from 497 nm out; 86 nm from the line | 010/9 | 320/10 -2° | 210/23 -9° | 210/34 -19° | 220/36 -25° | 230/31 -29° | 230/41 -33° | 230/38 -42° | |
| SAC | used from 646 nm out; 27 nm from the line | 110/6 | L/V 4° | 010/11 -2° | 350/11 -7° | 340/24 -16° | 360/44 -23° | 330/24 -30° | 270/21 -35° | 230/23 -43° |
| SFO | used from 745 nm out; 10 nm from the line | 120/13 | 090/14 5° | 040/14 -1° | 350/17 -5° | 360/42 -14° | 360/64 -23° | 350/38 -32° | 300/19 -37° | 250/18 -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 |
|---|---|---|---|---|---|---|---|
| GTF Great Falls, MT | departure | no report just now | 3,680 ft | ||||
| HLN Helena, MT | 60 nm out, 18 nm southeast of the line, tower | no report just now | 3,877 ft | ||||
| SMN Salmon, ID | 179 nm out, 19 nm southeast of the line | no report just now | 4,044 ft | ||||
| BOI Boise, ID | 308 nm out, 5 nm south of the line, tower | no report just now | 2,871 ft | ||||
| REO Rome, OR | 407 nm out, 16 nm northwest of the line | no report just now | 4,053 ft | ||||
| RTS Reno, NV | 596 nm out, 21 nm southeast of the line | no report just now | 5,050 ft | ||||
| MHR Sacramento, CA | 686 nm out, 9 nm southeast of the line, tower | no report just now | 98 ft | ||||
| CCR Concord, CA | 735 nm out, 3 nm southwest of the line, tower | no report just now | 25 ft | ||||
| SFO San Francisco, CA | destination | no report just now | 13 ft |
The highest airport on this list sits at 5,050 ft; the ground between airports is higher still. Check the sectional chart for the terrain and the minimum safe heights along the line.
At SFO when you get there the forecast at the estimated arrival, 5:57 am PDT (12:57 UTC)
SFO has no terminal forecast; use the nearest airport that does.
Temporary flight restrictions on the line or within 25 nm of it
- 6/3475 BEALE AFB, CA, Sunday, March 8, 2026 through Sunday, November 1, 2026 Local 8 nm from the route, 666 nm along the route · security · until 1 November · ZOA
- 6/7231 Santa Clara, CA, Sunday, October 11, 2026 through Monday, October 12, 2026 UTC 22 nm from the route, at the destination end · drones kept away from a public gathering · until 12 October · ZOA
Daylight
Sunset at GTF 6:41 pm MDT (00:41 UTC), at SFO 6:36 pm PDT (01:36 UTC) (civil twilight ends 7:02 pm PDT (02:02 UTC)). At 120 knots the arrival at SFO is before sunrise there (7:14 am PDT (14:14 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: Great Falls International, San Francisco International.