17.7 mapped river miles, draining 378 square miles, in the Roanoke basin watershed. 3 USGS gauges report water temperature on it, and this page reads all 3.
50°F and colder is cold, through cold-transitional and cool, to warm above 70°F — the same four bands, breaking at 58, 64 and 70°F, that the app paints. Grey is water nobody has measured.
Live from the USGS — every pill above is live, so the numbers you are reading are the latest continuous readings at each gauge. Provisional and unreviewed, as all real-time data is. If that fetch cannot happen — you are offline, or the USGS is down — the pills fall back to the last value we cached, 30 September 2026, 13:48 UTC.
This is inferred, not measured. Virginia DWR does not publish a temperature classification for this water. What it publishes is a management tier — whether the trout in it are wild, hold over through summer, or are stocked and fished out — and the bands below are read off that tier, because a stream that sustains wild trout is a cold stream and one that does not hold fish past July is not. It is the agency's judgement of the fishery translated into the four bands this site paints everywhere else; it is not a thermometer, and where the two disagree the thermometer is right.
Each gauge carries a July mean built from its own daily record — 8 Julys, 2019–2026, measured rather than modelled. A July mean is what decides which of the four bands a stretch of water belongs to, because July is when a trout river either holds or does not.
| Reach | July mean | Band | Groundwater |
|---|---|---|---|
|
Philpott RM 17.7–0.0 |
49.9 °F | cold | high |
|
Bassett RM -24.2–0.0 |
56.0 °F | cold | high |
|
Martinsville RM -32.8–0.0 |
49.9 °F | cold | high |
Every gauge sits at the bottom of its segment, so each number is the warm end and the water above it runs colder. ±1.99 °F on the fit.
Virginia DWR classifies this water as Class II, Class III, and Class V. More than one class appears because the classification changes along the river. The thermal bar above shows where. The management tier on those reaches is stocked holdover, wild. This is a designation of the fishery, not the season and creel rules — those change yearly and live with the agency.
Species Virginia DWR records in this water: brook trout, brown trout, rainbow trout. Recorded per classified reach, so it covers the classified water rather than the whole stream.
VDWR trout waters and stocking →
River miles are measured above the mouth, along the mapped mainstem. The reach breaks are the gauges, which is also how the temperature model divides the river.
| Reach | Miles | July mean | Access on it |
|---|---|---|---|
|
RM 17.7–0.0 down to Philpott |
42.0 | 49.9 °F | — |
|
RM -24.2–0.0 down to Bassett |
8.6 | 56.0 °F | — |
|
RM -32.8–0.0 down to Martinsville |
32.2 | 49.9 °F | — |
0 mapped access sites on the mainstem: 0 walk-in, 0 boat or canoe launches.
Every gauge on the mainstem, upstream first. Links go to the USGS monitoring-location page for the site.
Virginia DWR manages this water for brook trout, brown trout, rainbow trout. That is the state's designation rather than a survey: no fish survey or stocking record for this water is in the files this site reads.
The measured record behind every temperature band on this page: the mean of the daily means for July, at each gauge, over the years USGS has one.
| Gauge | July mean | July range | Julys |
|---|---|---|---|
| Philpott | 49.9 °F | 17.2 °F | 8 |
| Bassett | 56.0 °F | 20.8 °F | 7 |
| Martinsville | 49.9 °F | 17.2 °F | 8 |
56 insects are recorded from the Virginia mountains, which is the region this river sits in. That is a claim about the region and not a survey of this stream: nobody has recorded which of them has been caught here. Open the river in the app and the hatch panel will narrow it to the ones whose temperature window today's reading is inside.
| Insect | Peak | Water | Size |
|---|---|---|---|
| Little Black Stonefly Allocapnia / Capnia spp. |
January–April | 34–46°F | #16–18 |
| Little Brown Stonefly Taeniopteryx / Strophopteryx spp. |
February–April | 38–50°F | #12–16 |
| Blue-Winged Olive Baetis spp. |
March–May and September–November | 38–58°F | #16–22 |
| Quill Gordon Epeorus pleuralis |
March–April | 42–52°F | #12–14 |
| Blackfly Simulium spp. |
April–June | 40–65°F | #18–22 |
| Blue Quill Paraleptophlebia adoptiva |
April–May | 44–56°F | #16–18 |
| Cranefly Tipula spp. |
April–June and September–October | 40–65°F | #6–10 |
| Grannom Brachycentrus spp. |
April–May | 48–58°F | #14–16 |
| Green Rock Worm / Green Weenie Rhyacophila spp. |
April–June and September–October | 45–68°F | #10–14 |
| Hendrickson Ephemerella subvaria |
April–May | 45–58°F | #12–14 |
| Little Black Caddis Chimarra atterima |
April–May | 46–58°F | #16–20 |
| Alderfly Sialis spp. |
May–June | 52–66°F | #10–14 |
| Caterpillar Lepidoptera larvae |
May–September | 55–75°F | #8–14 |
| Crayfish Orconectes spp. |
May–October | 55–78°F | #4–8 |
And 42 more — the year-round records, mostly: midges, scuds and sculpins, which are in the water every day and are therefore never the news.
7 named streams meet this one. Confluence miles are above the mouth; the longest twelve are listed.
Smith River sits in HUC 8 03010101 and 03010103, the Roanoke basin, and drains 378 square miles, Strahler order 6 at the mouth. 134 NHD reaches carry the name for 55.5 miles in total — more than the 17.7 miles of drawn mainstem, because NHD counts side channels and braids as their own reaches.
The closest 6 rivers on this site, straight-line from the middle of this one — not drive time.