22 mapped river miles, draining 288 square miles, in the Lehigh River 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, 14:04 UTC.
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 |
|---|---|---|---|
|
Stoddartsville, Pa RM 22.5–0.0 |
71.2 °F | warm | low |
|
Lehigh R Bl Francis E Walter Res Nr White Haven Pa RM -2.9–0.0 |
69.1 °F | cool | moderate |
|
Glendon, Pa RM -47.0–0.0 |
74.6 °F | warm | low |
Every gauge sits at the bottom of its segment, so each number is the warm end and the water above it runs colder. ±2.48 °F on the fit.
PA DEP classifies this water as Cold Water Fishes, Trout Stocking, and Warm Water Fishes. 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 Cold Water Fishes, Trout Stocking, Warm Water Fishes. This is a designation of the fishery, not the season and creel rules — those change yearly and live with the agency.
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 22.5–0.0 down to Stoddartsville, Pa |
25.4 | 71.2 °F | 1 site — Route 33 Access |
|
RM -2.9–0.0 down to Lehigh R Bl Francis E Walter Res Nr White Haven Pa |
44.1 | 69.1 °F | — |
|
RM -47.0–0.0 down to Glendon, Pa |
36.0 | 74.6 °F | — |
1 mapped access sites on the mainstem: 0 walk-in, 1 boat or canoe launches. Source: PA DEP.
Every gauge on the mainstem, upstream first. Links go to the USGS monitoring-location page for the site.
17 units of public or open-access land touch this river, 1,076 acres in total. Acreage is the whole unit, not the part beside the water.
| Unit | Owner | Acres |
|---|---|---|
| Canal Park | city land | 138 |
| Lehigh Canal, Delaware & Lehigh Trail | city land | 36 |
| Lehigh Canal Park | city land | 34 |
| Walking Purchase Park | county land | 382 |
| Lehigh Canal Park (Freemansburg Borough) | city land | 14 |
| Riverside Tract | county land | 156 |
| Smith's Island | city land | 101 |
| Riverview Park | county land | 25 |
| Riverview Park | city land | 94 |
| Turkey Island | city land | 15 |
PA DEP designates this as trout water — Cold Water Fishes, Trout Stocking — without naming the species. 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 |
|---|---|---|---|
| Stoddartsville, Pa | 71.2 °F | 14.9 °F | 8 |
| Lehigh R Bl Francis E Walter Res Nr White Haven Pa | 69.1 °F | 10.4 °F | 8 |
| Glendon, Pa | 74.6 °F | 15.5 °F | 8 |
9 named streams meet this one. Confluence miles are above the mouth; the longest twelve are listed.
Lehigh River sits in HUC 8 02040106, the Lehigh River basin, and drains 288 square miles, Strahler order 5 at the mouth. 311 NHD reaches carry the name for 114.1 miles in total — more than the 22.5 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.