San Diego, CA to Sweet Grass, MT: 1,418 miles, 6 states, 407 numbered exits.
At 8 p.m. PDT, temperatures on I-15 run from 49°F near Spencer to 91°F near Fort Irwin, under mostly clear skies on average. Wind is light, gusting no higher than 19 mph anywhere on the road. No measurable rain is forecast on it in the next 24 hours.
Under an NWS alert now: Extreme Heat Warning · 120 mi
Read from the National Weather Service’s NDFD forecast grid at 2.5 km, sampled every eight miles along the pavement (run 10/03 01Z). The page is rebuilt every hour.
| Where | State | Now | Sky | Next 24 hours |
|---|---|---|---|---|
| Mile 0 · San Diego, CAExit 6B · El Centro / Beaches / Camino Del Rio South | CA | 81° | Clear | Dry |
| Mile 60 · Murrieta, CAExit 68 · Clinton Keith Road | CA | 84° | Clear | Dry |
| Mile 120 · Fontana, CAExit 129 · Cleghorn Road | CA | 76° | Mostly clear | Dry |
| Mile 180 · Barstow, CAExit 194 · Calico Road | CA | 85° | Mostly clear | Dry |
| Mile 240 · Baker, CAExit 259 · Halloran Springs Road | CA | 83° | Mostly clear | Dry |
| Mile 300 · Las Vegas, NVExit 25 · Sloan / Sloan Road | NV | 79° | Mostly clear | Dry |
| Mile 360 · Moapa Valley, NVExit 80 · Ute | NV | 89° | Mostly clear | Dry |
| Mile 420 · Saint George, UTExit 18 · Cedar Pocket | AZ | 81° | Partly cloudy | Dry |
| Mile 480 · Cedar City, UTExit 51 · Kanarraville / Hamilton Fort | UT | 67° | Mostly clear | Dry |
| Mile 540 · Beaver, UTExit 112 · Beaver | UT | 64° | Partly cloudy | Dry |
| Mile 600 · Holden, UTExit 174 · South Holden | UT | 68° | Partly cloudy | Dry |
| Mile 660 · Mona, UTExit 233 · Mona | UT | 64° | Partly cloudy | Dry |
| Mile 720 · West Jordan, UTExit 295 · 9000 South | UT | 71° | Partly cloudy | Dry |
| Mile 780 · Ogden, UTExit 357 · 750 North | UT | 71° | Partly cloudy | Dry |
| Mile 840 · Malad City, IDExit 17 · Weston / Preston | ID | 67° | Mostly cloudy | Dry |
| Mile 900 · Pocatello, IDExit 80 · Fort Halls | ID | 64° | Mostly clear | Dry |
| Mile 960 · Rexburg, IDExit 143 · Mud Lake / Rexburg | ID | 60° | Mostly clear | Dry |
| Mile 1020 · Lima, MTExit 9 · Snowline | MT | 49° | Clear | Dry |
| Mile 1080 · Dillon, MTExit 63 · Dillon / Twin Bridges | MT | 57° | Mostly clear | Dry |
| Mile 1140 · Butte, MTExit 127 · Harrison Avenue South | MT | 57° | Clear | Dry |
| Mile 1200 · Helena, MTExit 194 · Custer Avenue | MT | 60° | Mostly clear | Dry |
| Mile 1260 · Cascade, MTExit 256 · Cascade | MT | 63° | Partly cloudy | Dry |
| Mile 1320 · Brady, MTExit 321 · Collins Road | MT | 58° | Partly cloudy | Dry |
| Mile 1380 · Sunburst, MTExit 385 · Swayze Road | MT | 58° | Mostly cloudy | Dry |
| Mile 1394 · Sunburst, MTExit 394 · Ranch Access | MT | 56° | Partly cloudy | Dry |